Download NUCL 1 Early life of Albert Ghiorso: Preparation for future role as

NUCL 1
Early life of Albert Ghiorso: Preparation for future role as innovator and alchemist
Darleane Christian Hoffman, [email protected]. Division of Nuclear Science,
Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
Although young Albert was a good student in classical subjects, he early on showed his
mechanical ability. His family lived close to the Oakland Airport and Albert set his sights
on becoming an aeronautical engineer. When he graduated from high school in 1932 in
the depth of the Great Depression he could not find a summer job and spent his time
reading about radios and tinkering with building equipment. Albert's older sister was
able to obtain a small scholarship for him to study at UC Berkeley. He graduated in
1937, but there were still no jobs. He then designed and built specialized
communications equipment, and in 1941 joined a project to produce radiation detectors
for the Rad Lab at UC Berkeley. The contacts that he made there later enabled him to
join Glenn Seaborg's group at the Met Lab in Chicago from 1942-46 where he learned
the "new arts" of nuclear science. Ghiorso became indispensable for devising new and
improved detection methods for plutonium and then for still heavier elements. The rest
is history as Ghiorso went on to be co-discoverer/discoverer of the next 12 elements
beyond plutonium.
NUCL 2
Element: The amazing life and work of Albert Ghiorso
Robert W. Schmieder, [email protected]. Accelerator & Fusion Research,
Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
Albert Ghiorso is well-known to all nuclear scientists as the co-discoverer of 12
transuranic elements, partially through the large number of publications authored by A.
Ghiorso, et al. But unlike his lifelong collaborator Glenn Seaborg, his professional and
personal life is not well-known. I was a post-doc in Ghiorso's lab at Berkeley and
remained his friend until his passing in December 2010. From this 40-year friendship,
his professional records at the Berkeley Lab, and his personal records at his home, I am
preparing a full-length comprehensive biography of Albert Ghiorso, including the
scientific environment in which he worked and his personal life. The records explain
how this remarkable man was so successful in discovering new elements, and what he
did when the U.S. discontinued support for nuclear research in the 1970's. In this
presentation I will describe the amazing life of Albert Ghiorso, the scientist and the man.
NUCL 3
Recollections of the late Albert Ghiorso: Comments on his scientific
accomplishments, my perceptions on the far-reaching impact of his efforts and
his philosophy of doing science
Richard G. Haire, [email protected]. Transuranium Research Laboratory, Oak
Ridge National Laboratory, Oak Ridge, TN 37831, United States
Albert Ghiorso is a legend to scientists knowledgeable of the actinide and transactinide
elements. He was a co-discover of twelve transuranic elements and projected an image
of both a scholarly professor as well as an extraordinary “hands-on” laboratory scientist.
Of special interest to Al was using einsteinium-254 for production of transactinide
elements. As a competitor for the Es-253/Es-254 High Flux Isotope Reactor (HFIR)
products at Oak Ridge National Laboratory, I had to recover all the Es used in our
chemical studies so that the longer-lived Es-254 could then be used for Lawrence
Berkeley Laboratory accelerator targets. When the concept of the “LEAP” project
evolved (Large Einsteinium Activation Program), Al and I had interesting discussions
about making and handling 40 microgram Es-254 targets. I am pleased to pass along
thoughts about Al and comments from our discussions.
NUCL 4
Personal reflections on the legacy of the ultimate alchemist Albert Ghiorso
David E. Hobart, [email protected]. Chemistry Division, Los Alamos National
Laboratory, Los Alamos, New Mexico 87545, United States
In 1990 Al Ghiorso and I were both invited by Glenn Seaborg to present papers at the
Welch Foundation Conference: “Fifty Years with Transuranium Elements” in Houston,
TX. I met Al there and introduced myself. At that time he was grousing about the
swirling transfermium controversy and the proposed renaming of Element 105 as
Dubnium replacing Hahnium. Later in March 2006 I introduced Al at the Einstein Society
Gala in Albuquerque, NM where he was honored with the “National Nuclear Science
Award” by the National Atomic Museum Foundation. In 2006 I invited Al to present the
keynote address at the “Analytical Chemistry in Nuclear Technology Symposium” at the
San Francisco ACS meeting where he discussed analysis of the mysterious 1949
nuclear explosion in the Soviet Union. Albert Ghiorso was a modest unassuming
gentleman and a legend in nuclear science and I am honored to reflect on my memories
of him.
NUCL 5
Element 110 experiment
Walter D Loveland, [email protected]. Department of Chemistry, Oregon State
University, Corvallis, OR 97331, United States
The experiment designed to synthesize element 110 with the 209Bi(59Co,n) reaction was
not one of Al Ghiorso's most successful experiments. However the experiment is
illustrative of Al's style of doing experiments, his innovative solutions to difficult
problems and his ability to persevere in the face of adversity, both experimental and
political. It is now thought that one atom of 267Ds was made in this experiment. I will
review the details of the experiment as gleaned from the original logbooks for the
experiment. I will discuss the result in light of our current understanding of the structure
of nuclei in this region and heavy element production cross sections
NUCL 6
Elemental challenge: Approval of Ghiorso's proposal of the name "seaborgium"
for element 106
Darleane Christian Hoffman, [email protected]. Nuclear Science Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, United States
When the confirmation of the 1974 discovery of element 106 was published in Phys.
Rev. Letters in 1994, the discovery group began to think about naming it. There were
many discussions and proposals, but the more co-discoverer Albert Ghiorso thought
about it the more he believed that "in the great panoply of names already picked for the
heavy element region the name 'seaborgium' would be of equal worth to curium,
einsteinium, fermium, mendelevium, lawrencium, rutherfordium, hahnium, nielsbohrium,
and meitnerium" (The names hahnium and nielsbohrium did not survive the final IUPAC
1997 compromise agreement and approval). Ghiorso obtained a consensus of support
from the discovery group and many others, and finally from Seaborg's wife Helen, and
then from Glenn Seaborg himself. The long struggle for IUPAC approval and some of
the 'inside story', the 'deals', and widespread international support required before final
approval of 'seaborgium' in 1997 will be discussed.
NUCL 7
Award Address (Glenn T. Seaborg Award for Nuclear Chemistry sponsored by the
ACS Division of Nuclear Chemistry and Technology). Radiochemistry adventures:
Medical, environmental and biological applications of radiotracers
Silvia S. Jurisson, [email protected]. Chemistry, University of Missouri,
Columbia, MO 65211, United States
The inorganic and radiochemistry of technetium, rhenium, rhodium, gold, the
lanthanides, gallium, indium, arsenic and others have been and continue to be
investigated for potential medical, environmental and biological applications. Both the
bifunctional chelate approach (Rh-105, Au-199, radiolanthanides) and the integrated
approach (Tc-99m, Re-188) have shown utility for targeting receptors on tumor cells
(e.g., melanoma, prostate cancer). Understanding the basic chemistry of technetium
with sulfide may lead to improved methods for separations and storage in nuclear fuel
cycle chemistry as Tc-99 is a fission product. Development of high specific activity
radionuclides (e.g., Rh-105, Re-186, As-72) may yield a larger suite of potential
radiotherapeutic or radiodiagnostic agents. Probing plant biochemistry with radiotracers
may lead to understanding metal ion transporters and/or potential phytoremediation.
Radiotracers have applications in many scientific arenas and continue to lead to new
and interesting discoveries.
NUCL 8
In vivo molecular imaging with the short lived positron emitters
Joanna S. Fowler, [email protected]. Medical, Brookhaven National Laboratory, Upton,
NY 11973, United States
In vivo molecular imaging using organic compounds labeled with the short lived positron
emitters, carbon-11 (t1/2: 20.4 min), fluorine-18 (t1/2: 110 min) and nitrogen-13 (t1/2: 10
min) and positron emission tomography (PET) have emerged as an important scientific
tools to quantify the distribution and kinetics of chemical compounds in living systems in
real time and at true tracer levels. While applications in clinical research and diagnosis
abound, this technology is also being broadened to include energy and environmental
applications. Progress continues to be tightly coupled to innovation in radiotracer
chemistry, particularly in the development of rapid radiosynthetic methods for a wide
variety of biologically relevant chemical compounds. Here we highlight the role of
radiotracer chemistry in enabling the application of this technology to problems of broad
public impact. Supported by the U. S. Department of Energy, Office of Biological and
Environmental Research and National Institutes of Health.
NUCL 9
Single step labeling approach to fluorine-18 prosthetic agents
Shorouk F. Dannoon, [email protected], Joseph E. Blecha, Cindy T Lau,
Henry F VanBrocklin. Radiology and Biomedical Imaging, University of California San
Francisco, San Francisco, CA 94107, United States
Labeling peptides, proteins and antibodies with fluorine-18 (18F-) has been performed
using prosthetic groups such as N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB) and N[6-(4-[18F]fluorobenzylidene)aminooxyhexyl]maleimide ([18F]FBAM). However, these
labeling methods often require multiple steps and results in low radiochemical yields.
Consequently, the search has been ongoing to develop a one step labeling prosthetic
group. A new class of chloropyrimidine compounds with different electron
withdrawing/donating groups at the position meta to the chloro leaving group were
investigated. The 18F- radiolabeling was performed with the standard resolubilization
method (drying the 18F- prior to labeling) and with the aqueous labeling conditions
developed in our laboratory using the microfluidics. Labeling was achieved and the
radiochemical yields varied as a function of the functional group and labeling method.
The resultant [18F]fluoropyrimdines were stable up to 24 hrs. This represents a
promising single step labeling approach for new 18F- prosthetic groups.
NUCL 10
F-18-labeled myocardial perfusion agents based on rhodamine dyes
Alan B. Packard, [email protected], Mark D. Bartholoma, Frederic
H. Fahey, S. Ted Treves. Division of Nuclear Medicine, Children's Hospital
Boston/Harvard Medical School, Boston, MA 02115, United States
Myocardial perfusion imaging (MPI) is important in the assessment of cardiac function,
and as rhodamine dyes are known to accumulate in the myocardium, we are evaluating
F-18-labeled rhodamines as possible PET MPI radiopharmaceuticals.
The ω-F-18-esters of several rhodamines (B, 110, and 6G) were prepared from the
lactones and the tosyl alkyl fluorides (ethyl, propyl, diethyleneglycol, and
triethyleneglycol). The biodistribution was measured in rats, infarct imaging was
evaluated in a coronary artery ligation model, and mitochondrial uptake was assessed
in vitro.
The F-18-labeled diethylene glycol ester of rhodamine 6G showed the best combination
of high uptake in the heart and rapid clearance from non-target tissues. In the rat infact
model, perfusion defects were clearly visualized. The ex vivo rat myocyte model
demonstrated that the compound rapidly accumulates in mitochondria.
These results strongly suggest that F-18-labeled rhodamine 6G is a very promising
candidate for clinical evaluation as a PET MPI radiopharmaceutical.
NUCL 11
Pb-212 radioimmunotherapy – observations along a lengthy long road forward
Kwon J. Yong, Kwamena E. Baidoo, Diane E. Milenic, Martin W Brechbiel,
[email protected]. Radioimmune & Inorganic Chemistry Section, National Cancer
Institute, Bethesda, MD 20892, United States
Radioimmunotherapy (RIT), using an alpha-emitter provides an efficient tool for cancer
therapy, far better suited than β--emitters for treating small tumor burden and
micrometastases. Pb-212 RIT pre-clinical trials have been performed in animal models
ultimately directed towards translation to an appropriate clinical trial. Along this road,
assumptions and standards regarding mechanisms of action were made, yet a dearth of
in vivo data exists for their basis. In addition to providing an overview of Pb-212 RIT
past, present, and future, results from studies elucidating mechanisms by alpha-particle
RIT, specifically effects from Pb-212-TCMC-trastuzumab, e.g., induction of DNA double
strand breaks, blockage of DNA damage repair by interference with RAD51, and
induction of cell death, but not via caspase-3 apoptosis, will be presented to define a
better understanding of the in vivo mechanism of alpha-particle RIT to generate
information to optimize usage of chemotherapeutics in combination with alpha-particle
RIT.
NUCL 12
Targeted antisense radiotherapy using a 177Lu-labeled peptide nucleic acid in Bcell non-Hodgkin's lymphoma
Michael R. Lewis1,2, [email protected], Ethan R. Balkin3, Fang Jia2. (1)
Department of Research, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
65201, United States (2) Department of Veterinary Medicine and Surgery, University of
Missouri, Columbia, MO 65211, United States (3) Department of Pathobiology,
University of Missouri, Columbia, MO 65211, United States
The B-cell lymphoma/leukemia-2 (bcl-2) proto-oncogene is a dominant inhibitor of
apoptosis in B-cell non-Hodgkin's lymphoma (NHL). Our goal was to develop a
radiolabeled bcl-2 antisense peptide nucleic acid (PNA)-Tyr3-octreotate conjugate
designed for dual modality NHL therapy, consisting of a radiopharmaceutical capable of
simultaneously down-regulating apoptotic resistance and delivering cytotoxic internally
emitted radiation. This conjugate was radiolabeled with 177Lu by conjugating the PNApeptide to 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA). The
biodistribution of the 177Lu-labeled bcl-2 antisense PNA-peptide showed specific tumor
targeting in mice bearing Mec-1 human NHL xenografts. In vivo tumor saturation studies
determined that 50 µg of the compound provided the maximum antisense effect.
Compared to controls, preliminary radiotherapy studies showed a significantly longer
tumor growth delay in mice treated with the 177Lu-labeled antisense PNA-peptide. This
effect was most noticeable when 50 µg of the unlabeled compound was administered 1
h after injection of 120 µCi of the radiolabeled PNA-peptide.
NUCL 13
Strategies for improving specific activity and biodistribution of copper-64-labeled
anti-EGFR antibody cetuximab
Carolyn J Anderson1,2,3, [email protected], Yunjun Guo1,2, Dexing Zeng3,
Riccardo Ferdani1. (1) Department of Radiology, Washington University, St. Louis, MO
63110, United States (2) Department of Chemistry, Washington University, St. Louis,
MO 63130, United States (3) Department of Radiology, University of Pittsburgh,
Pittsburgh, PA 15219, United States
Cetuximab was the first monoclonal antibody targeting EGFR that was approved by the
FDA for the treatment of metastatic colorectal and head & neck cancer. We previously
showed that Cu-64 labeled DOTA-cetuximab is a potential tracer for PET imaging of
EGFR-positive tumors; however, poor in vivo stability caused suboptimal tumor:nontumor ratios. Here we compare DOTA to CB-TE1A1P, a cross-bridged macrocyclic
chelator that allows for Cu-64 radiolabeling at lower temperatures. Biodistribution of this
new compound in nude mice bearing human colorectal tumors (HCT116) was
compared with 64Cu-DOTA-cetuximab, and showed improved blood clearance and
lower liver uptake. The tumor: non-tumor ratios for Cu-64-CB-TE1A1P-cetuximab at 24
and 48 h are significantly higher than 64Cu-DOTA-cetuximab. A drawback of CBTE1A1P-cetuximab is that low specific activities are achieved with Cu-64 labeling due to
conjugation techniques. Novel click-based methodologies for improving specific activity
will be discussed.
NUCL 14
Production of high purity and high specific activity radioisotopes
Cathy Cutler1, [email protected], Nebiat Sisay2, James Kelsey1. (1) University of
Missouri Research Reactor, University of Missouri, Columbia, Missouri 65211, United
States (2) Department of Chemistry, University of Missouri, Columbia, Missouri 65211,
United States
High purity and high specific activity radionuclides are criticial for use in environmental
studies, evaluation of biological processes in plants and animals and in medicine for
treatment and diagnosis. A need exists for isotopes that can be used for associated
diagnosis and therapy coined as “Theragnostic Medicine.” This can either be done
through the use of a single isotope that can be utilized in both imaging and therapy such
as Lu-177 and many of the radiolanthanides, or the use of “matched
diagnostic/therapeutic” pairs of radionuclides such as Tc-99m and Re-186 or Au-199
and Au-198. MURR is actively developing novel production and purification methods of
radioisotopes with potential use in a variety of applications. Current efforts have focused
on developing high specific activity radioisotopes which can be attached to
biomolecules or nanoparticles that are taken up selectively by diseased tissues, thus
delivering toxic radioactivity to diseased tissue while minimizing or sparing damage to
healthy or normal cells. The development of these production methods and
radioisotopes will be discussed in the context of their physical and chemical properties
as related to their potential utility in medical research.
NUCL 15
Our scientific lives with Lester: Over forty years of collaboration
Norman M Edelstein1, [email protected], Jean Fuger2. (1) Chemical Sciences
Division, MS 70A-1150, Lawrence Berkeley National Laboratory, Berkeley, CA 94720,
United States (2) Institute of Radiochemistry, University of Liège-Sart Tilman, B-4000
Liège, Belgium
Lester Morss was a graduate student in chemistry at the University of California,
Berkeley, in the late 1960s. He performed his Ph.D. work in the group of Professor
Burris B. Cunningham, a renowned actinide microchemist. During this time both NME
and JF first interacted with Lester on various projects. From these beginnings, we
continued our scientific collaborations up to the present time. Our personal scientific
recollections will be discussed during this presentation.
NUCL 16
Curium as a favorite element: The Lester Morss effect
L. Soderholm, [email protected]. Chemical Sciences and Engineering Division, Argonne
National Laboratory, Argonne, IL 60439, United States
Curium (Cm) is the actinide element that sits directly under Gd in the periodic table and
as such closely shares much of its solution chemistry. For example, one of the current
dilemmas in nuclear reprocessing is how to affect lanthanide/actinide separations,
notably those involving Cm. Both in solution and in the solid state Gd and Cm exist
predominantly as trivalent ions, with spherically symmetric ground states as defined
within the Russell Saunders formalism, making them ideal candidates for theoretical
studies and properties characterization. In contrast to Gd chemistry, Cm also has a
tetravalent oxidation state that is particularly accessible in the solid state, complicating
the understanding of the role of redox chemistry and bonding properties when
interpreting the optical, structural, and magnetic data obtained from its compounds.
Work to unravel this intriguing chemistry will be discussed, with emphasis on solid-state
behaviors. This work was performed for the DOE, OBES, under contract DE-AC0206CH11357.
NUCL 17
Recent advances in the recovery and purification of actinium isotopes
E. Philip Horwitz1, [email protected], Daniel R McAlister1, James T Harvey2. (1) PG
Research Foundation, Inc., Lisle, IL 60532, United States (2) Northstar Medical
Radioisotopes, Madison, WI 53703, United States
It is noteworthy that there is far less information on the chemistry of the element
actinium than for most of the elements of the actinide series. The reason for this scarcity
may be explained, in part, by the lack of availability of actinium isotopes, particularly
225
Ac (half-life 10.0 days) and 227Ac (half-life 21.77 years). However, with the increased
interest in alpha immunotherapy, there has been a need to simplify the recovery and
purification of actinium isotopes.
We have developed two highly efficient classes of extraction chromatographic resins for
the recovery and purification of Ac from 229Th/225Ra sources, proton bombarded 232Th
targets, 227Ac/Be neutron sources and natural uranium. The first class of resins is based
on di-alkyl phosphoric and phosphonic acid extractants. The second class of resins is
based on the tetra-alkyl diglycolamides moiety. Flowsheets demonstrating the use of
these resins will be presented.
NUCL 18
Application of the Hubbard model to Cp*2Yb(bipy), a model system for exchangecoupled lanthanide single molecule magnets
Wayne Lukens, [email protected], Nicloa Magnani, Corwin Booth. Chemical Sciences
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United
States
A straightforward model based on the well-known Hubbard model is applied to systems
in which magnetic metal ions have direct overlap with radical-bearing ligands. The
Hubbard model explicitly addressed electron correlation, which is essential for
understanding the magnetic behavior of multiconfigurational complexes, especially
lanthanide and actinide complexes. This model is applied quantitatively to Cp*2Yb(bipy)
to explain the very strong exchange coupling (2J ∼ 900 cm-1) in this complex. The
model is also used to explain the presence of strong exchange coupling in the recently
reported lanthanide single molecule magnets (SMMs) in which the lanthanide spins are
coupled via bridging ligands possessing unpaired spins. The results suggests that
increasing the magnetic coupling in lanthanide clusters could lead to a tremendous
increase in the operating temperatures of future SMM-containing devices and suggest
routes to the rational design of future lanthanide SMMs.
NUCL 19
Review of ground-state properties of PuO2, AmO2, and CmO2
Gerard H Lander, [email protected] Commission, JRC, Institute for Transuranium
Elements, Karlsruhe, Baden-Wurtembourg 76125, GermanyInstitut Laue Langevin,
Grenoble, Isere 38042, France
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Experimental investigations of the actinide dioxides have been conducted since the
1940s. Apart from the complexities of stoichiometry, the ground-state properties are
considered well known. Recently, for example, we have published a complete account
of the ground state of UO2, including the dynamics of the ordered state [1]. However, in
the case of the heavier actinides the situation is not clear; our understanding is by no
means complete. This talk will review the experimental situation, particularly evoking the
noteworthy paper [2] on CmO2 by Morss et al. The number of recent experimental
investigations has, alas, decreased on transuranium materials, but, in contrast, there
have been many theories published addressing the ground-state properties.
[1] R. Caciuffo et al., Phys. Rev. B 84 , 104409 (2011)
[2] L. R. Morss et al., J. Less Comm. Metals 156 273 (1989)
NUCL 20
One century of divalent rare-earth metal chemistry
Gerd H Meyer, [email protected]. Department of Chemistry, Universität zu
Köln, Cologne, NRW 50939, Germany
The rare-earth elements R in the divalent state, R2+, form binary and complex halides
which may be divided into two groups. Group I contains, with the typical example of
EuI2, those elements which have stable 4fn5d0 configurations; the R2+ ions behave
structurally just like alkaline-earth ions of the same size. The 4f electrons behave like
core electrons. Group II comprises elements with 4fn-15d1 configurations; LaI2 would be
a typical example of a binary halide of that group. The 5d electron behaves as a typical
valence electron and may either contribute to covalent metal-metal bonding or cause
electronic conductivity. It may also, at low temperatures, be localized. Examples are
rare in halides. There is, however, a growing organometallic chemistry in which the 5d
electron of R2+ is trapped and involved in R―C bonding.
NUCL 21
Near-infrared photoluminescence of neptunyl and plutonyl ions
Marianne P Wilkerson1, [email protected], Beau J Barker2, John M Berg3. (1) Chemistry
Division - Nuclear and Radiochemistry, Los Alamos National Laboratory, Los Alamos,
NM 87545, United States (2) Department of Chemistry, Emory University, Atlanta,
Georgia 30322, United States (3) Manufacturing Engineering and Technology Actinide Processing Support, Los Alamos National Laboratory, Los Alamos, NM 87545,
United States
The actinyl ions, AnO22+ (An = U, Np, Pu, and Am), are a series of linear dioxo dications
that dominate the chemistry of the light actinides in their higher oxidation states.
Theoretical and experimental studies have been reported on the nature of the bonding
in this structural motif. We will discuss photoluminescence emission measurements
between 6000 and 10,200 cm-1 from crystalline Cs2U(Pu)O2Cl4 both at room
temperature and cooled to 75 K. Pulsed laser excitation between 625-1200 nm
produces rich emission spectra that are more complex than the electronically simpler 5f1
Cs2U(Np)O2Cl4 system, as one would expect. Photoluminescence decay dynamics, and
excitation energy dependence indicate multiple emitting states and complex decay
pathways.
LA-UR 11-05998
NUCL 22
Stability of transactinide elements and their nuclear structure
Irshad Ahmad, [email protected] Division, Argonne National Laboratory,
Argonne, IL 60439, United States
The first transuranium element neptunium (Z=93) was discovered by McMillan and
Abelson in 1940. Since then elements all the way up to Z=118 have been discovered. It
has been shown that the stability of superheavy elements with Z ~ 114 is due to the
shell correction energy. Experiments and theoretical calculations show that proton (and
neutron) single-particle spectra have gaps at certain proton (and neutron) numbers.
These are called magic numbers and nuclei with these numbers of protons (and
neutron) have enhanced stability. For protons, the last known magic number is 82 and
for neutrons it is 126. Theoretical calculations using different models predict next magic
proton numbers of 114, 120 and 126 but the neutron magic number is the same (184)
for all models. Nuclear stability increases with increase in nuclear shell energy. Shell
correction energy depends on the distribution of single-particle levels near the Fermi
surface. We have been studying the single-particle level energies in the actinide
elements for many years. In particular, we have extensive data for proton states in Bk (Z
= 97) and Es (Z = 99) nuclei and for neutron single-particle states in 251Cf and 249Cm.
The experimental energies of single-particle states provide a test for various theoretical
models. These models then calculate the single-particle spectra which are used to
determine the shell correction energy. Data available on single-particle level energies
will be presented and its significance for the stability of the superheavy elements will be
discussed.
*Work supported by the U.S. Department of Energy, Office of Nuclear Physics, under
contract No. DE-AC02-06CH11357.
NUCL 23
Cation-cation interactions in uranyl tungstates
Enrica Balboni, [email protected], Peter C Burns. Department of Civil Engineering and
Geological Sciences, University of Notre Dame, Notre Dame, IN 46556, United States
The crystal chemistry of uranyl compounds containing tetrahedrally coordinated
hexavalent cations is diverse owing to the variability in coordination geometries and
linkage of polyhedra. Uranyl tungstates are an interesting group of compounds with the
potential to exhibit novel topologies. W 6+ occurs in various coordination numbers (4, 5
and 6), and the larger coordination numbers permit uranyl tungstates to form high
dimensional topologies. Here we report the structure and characterization of new uranyl
tungstates containing cation-cation interactions obtained by hydrothermal synthesis
between 220 and 265 °C and their relationships with other actinide materials. A cationcation interaction in actinide chemistry is where an O atom of an actinyl ion coordinates
a second actinyl ion. These interactions are common for pentavalent actinides, but
account for only about 2% of the structures of U(VI) uranyl compounds. Where present,
cation-cation interactions permit a closer-packed structure with higher density, and favor
formation of framework structures.
NUCL 24
Computational studies of actinide and lanthanide complexes
David A Dixon, [email protected]. Department of Chemistry, The University of
Alabama, Tuscaloosa, AL 35487-0336, United States
Advances in theory, algorithms, software, and computer architectures, have made it
possible to begin to calculate reliably the properties of actinide and lanthanide
complexes. We are interested in the prediction of such properties, especially
thermodynamics in the gas and aqueous solution phases, using molecular orbital theory
and density functional theory. The properties of uranyl phosphate complexes will be
described. The properties and hydrolysis of thorium oxide complexes will be described.
The reactions of lanthanide atoms with fluoro-substituted methanes will be described. In
addition, the differences between thorium (IV) compounds and other metal (IV)
compounds will be discussed.
NUCL 25
Ligand design in aqueous separation systems of lanthanides and actinides
Kenneth L Nash, [email protected]. Department of Chemistry, Washington State
University, Pullman, WA 99164-4630, United States
During his distinguished career in actinide science, Lester Morss is best known for his
work in actinide thermodynamics, emphasizing the properties of binary compounds. For
some portion of his active research career, Lester applied his deep understanding of
thermodynamics to studies of lanthanide and actinide complexation by polydentate
chelating agents relevant to separations applications. His work on tetramethylpyridyl
ethylene diamine (TPEN) and on tetrahydrofuran-2,3,4,5-tetracarboxylic acid addressed
the separation potential of polyaza complexing agents and of the effects of ligand
structure on actinide-lanthanide selectivity. These themes are of continuing interest in
the development of new separation reagents for actinide separations in advanced
nuclear fuel cycles. In this presentation, Lester's contributions to this field will be
discussed in the context of continuing efforts to advance the science of ligand design for
separations applications.
NUCL 26
Somatostatin analogs cyclized via Re/Tc chelation: Examining the interplay
between receptor affinity and metal coordination stability
Heather M Hennkens1, [email protected], Shorouk F Dannoon2, Silvia S
Jurisson2, Michael R Lewis1,3. (1) Department of Veterinary Medicine and Surgery,
University of Missouri-Columbia, Columbia, MO 65211, United States (2) Department
of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, United States (3)
Department of Research, Harry S Truman Memorial Veterans' Hospital, Columbia, MO
65201, United States
With the ultimate goal of designing somatostatin receptor (SSTR)-targeting peptides
with stable, direct radiometal coordination and high tumor uptake and retention, a small
library of Re-cyclized peptides were synthesized and evaluated for their SSTR affinities.
Structural modifications to the base peptide sequence, Tyr-3-octreotate (dPhe-Cys-TyrdTrp-Lys-Thr-Cys-ThrOH), included acetylation of the peptide N-terminus, insertion of a
third Cys residue into the peptide sequence, replacement of dPhe 1 with Cys/dCys,
and/or replacement of Cys2 with a synthetic bidentate cysteine derivative. Translation to
Tc-99m peptide cyclization was performed on a subset of the peptides with varying
SSTR affinities. In vitro stability studies carried out in phosphate buffered saline, mouse
serum and cysteine solutions led to the selection of three Tc-99m-cyclized peptides for
normal mouse biodistribution studies. This retrospective assessment examines the
various metal coordination motifs produced and the interplay between radiometal
coordination stability and somatostatin receptor affinity.
NUCL 27
Design and development of radiometallated E.Coli STh conjugates for molecular
imaging of human colon cancers
Wynn A. Volkert, [email protected]. Departments of Radiology and Chemistry,
University of Missouri, Columbia, MO 65211, United States
The aim of these studies was to develop new radiometallated E. Coli STh analogs for
specific in vivo targeting of guanylin/guanylate cyclase-C [GC-C] receptors that have
been shown to be expressed in high densities on the surface of primary and metastatic
human colon cancer cells. STh is a 19 amino acid tri-disulfide peptide and reproducible
production of the correct conformer of STh-conjugates is challenging. Synthesis of SThDOTA conjugates was accomplished by air-oxidation of the linear peptide and selective
sequential deprotection of thiol groups, followed by susequent HPLC purification.
Studies with 111In-DOTA-STh (1-19) conjugates demonstrated their high in vitro binding
affinity [i.e., in 1 – 20 the nMolar range] to GC-C receptors expressed on T84 human
colon cancer cells, selective uptake in T84 xenografts in SCID mice, along with rapid
blood clearance and minimal liver uptake. These results indicate their potential as
molecular imaging radiopharmaceuticals for colon cancer.
NUCL 28
Useful in vivo probe for the sigma-1 receptor: 1-(3-[I-125]-Iodobenzyl)-4benzylpiperazine ([I-125]-IDBP)
Susan Z Lever1,2, [email protected], Kuo-Hsien Fan1, Emily A FergasonCantrell3,4, Terry L Carmack5, Lisa D Watkinson5, John R Lever3,4,5,6. (1) Chemistry,
University of Missouri, Columbia, Missouri 65211, United States (2) Research Reactor
Center, University of Missouri, Columbia, Missouri 65211, United States (3)
Department of Radiology, University of Missouri, Columbia, Missouri 65211, United
States (4) Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri 65211,
United States (5) Radiopharmaceutical Sciences Institute, University of Missouri,
Columbia, Missouri 65211, United States (6) Medical Pharmacology and Physiology,
University of Missouri, Columbia, Missouri 65211, United States
Sigma-1 receptor ligands (3-chlorobenzyl)- and (3-methoxybenzyl)-4-benzylpiperazine
(ClDBP and MeODBP) attenuate cocaine-induced convulsions in mice after i.p.
administration (Foster et al., Bioorg Med Chem Lett 13: 749-751, 2003). However,
dosages reaching the brain were not measured. To examine structure-activity
relationships and to assess brain delivery, analogs IDBP and [I-125]-IDBP were
synthesized. IDBP exhibited high affinity and selectivity for sigma-1 receptors (Ki sigma1, 0.26 ± 0.1 nM; Ki sigma-2, 17.7 ± 1.1 nM). Radioiododestannylation afforded [I-125]IDBP in 77% yield and > 99% purity. Despite a log D7.4 of 3.81, [I-125]-IDBP brain
uptake was 4.06 ± 0.13 % ID/gm at 15 min and 0.80 ± 0.08 % ID/g at 2 h that was
blocked by sigma-1 receptor antagonist BD1063. Cerebral [I-125]-IDBP specific binding
was inhibited more potently by MeODBP (0.26 umol/kg) than by ClDBP (0.39 umol/kg).
Thus, [I-125]-IDBP is a useful radioligand for in vivo studies of sigma-1 receptors.
NUCL 29
Developing click reactions for facile coupling of Re/99mTc(CO)3 to biomolecules
Paul D Benny, [email protected]. Department of Chemistry, Washington State
University, Pullman, WA 99164-4630, United States
Radiolabeling biomolecules with M(OH2)3(CO)3+ (M= Re/99mTc) can present unique
challenges in the number of species observed compared to small molecules for
targeting. The ability of the metal to specifically complex a desired ligand compared to
non-specific binding modes of peptides that are rich in histidine residues can
significantly hinder the stability and the function of radiolabeled biomolecule. Whereas,
click reactions provide an alternative paradigm to improve the site specificity by
prelabeling the radiometal with a ligand followed by reaction of orthongonal functional
groups. A series of click reactions (i.e., catalytic, photochemical, reactive functional
groups) were investigated with M(OH2)3(CO)3+ (M= Re/99mTc) to compare the conditions
and efficiency of the click reaction under stable and radiochemical conditions.
NUCL 30
DOE radiochemistry program
Prem C Srivastava, [email protected]. Office of Science, Biological
and Environmental Research, U.S. Department of Energy, Washington, DC 205851290, United States
The program supports fundamental research for developing new methodologies for realtime, high-resolution imaging of dynamic biological processes in living systems. This
research has two integrated goals: (1) the research supports the DOE Science missionrelated activities in bioenergy and bioremediation; and (2) the fundamental
methodologies developed under the DOE program may serve as tools leading to
transformational new technologies for use in nuclear medicine research supported by
NIH and industry. Radiochemistry research involves improvements in the synthetic
methodology for incorporating the radionuclides to allow dual or multiple labeling of the
targeting molecule for dual energy or hybrid imaging techniques to study biological
process in living systems. Radionuclide imaging instrumentation research is focused on
increasing the accuracy of quantitative assessments of the radiotracers in living
systems. The program also supports integrated involvement of graduate students and
postdoctoral fellows through radiochemistry research projects of excellence grants to
universities.
NUCL 31
In vivo pharmacoknietics evaluation of gold nanocage for photothermal therapy
Yongjian Liu1, [email protected], Yucai Wang2, Xiaohu Xia2, Hannah Kutosky1,
Paige Brown2, Chad Jarreau1, Miaoxin Yang2, Cathy Cutler3, Younan Xia2, Michael
Welch1. (1) Radiology, Washington University, St. Louis, MO 63110, United States (2)
Biomedical Engineering, Washington University, St. Louis, MO 63110, United
States (3) Research Reactor Center, University of Missouri, Columbia, MO 65211,
United States
Metal nanoparticles have received considerable attention for cancer diagnosis and
therapy. Gold nanostructures with optical properties tunable in the near-infrared (NIR)
region (650 to 900 nm) are particularly attractive for hyperthermia based on the
photothermal effect. The hollow gold nanocages (AuNC) have a number of unique
features including well-defined structure, straightforward preparation, and high
absorption in NIR these make them particularly attractive as a new class of
photothermal transducers for therapeutic applications. Thus, a series of AuNC with
different sizes and surface plasmon resonance peaks were prepared. The surfaces of
these nanocages were functionalized with polyethylene glycol of difference lengths and
coverage. The in vivo pharmacokinetics of these pegylated AuNC were evaluated by
radiolabeling with Cu-64 and Au-198 and biodistribution. The non-specific uptakes by
the enhanced permeability and retention effect was also explored in roden tumor model
with optimized construction of AuNC.
Acknowledgment: This work is supported by NCI grant (5R01CA138527-02).
NUCL 32
Metal-organic capsules for diagnosis and therapy
Jerry L. Atwood, [email protected], Andrew V. Mossine, Harshita Kumari, Drew
A. Fowler, Nathaniel J. Schuster. Department of Chemistry, University of MissouriColumbia, Columbia, MO 65211, United States
The enclosure of chemical space is one of the essential attributes of a biological
system. We have previously shown that macrocycles can serve as building blocks for
very large assemblies. In particular, calixarenes and resorcinarenes may be used to
enclose space in a manner consistent with the principles of solid geometry attributed to
Plato and to Archimedes. The ability of macrocycles to effect the construction of
hydrogen-bonded spherical molecular capsules is due to focused functionality. The use
of pyrogallol[4]arenes to form hydrogen bonded hexamers and dimers is noteworthy.
These hydrogen bonded molecular capsules are both stable and soluble in polar liquids.
Recently, we have used Cu2+ and Ga3+ ions to replace some or all of the hydrogen
bonds, affording robust capsules. In work yet to be published, we have utilized most of
the first row transition metals to seam dimeric and hexameric capsules. Current efforts
involve the incorporation of metal radioisotopes into the framework of the capsules, and
as guests within the nanocapsules.
NUCL 33
Applications of radiochemistry to nanoscience
John D Robertson, [email protected], Mark McLaughlin, Isaac Simmonds.
Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211,
United States
Neutron activation analysis (NAA) is a powerful radiochemical technique for the analysis
of nanomaterials in a wide variety of matrices. In the majority of applications, the sample
or system is transparent to both the neutron probe and the gamma-ray analytical signal.
We are currently developing a system of lanthanide phosphate based nanoparticles for
use as tagging and tracking agents. The composition of the nanoparticles can be varied
to provide a unique signature that can be rapidly and precisely measured in the field via
neutron activation analysis. Likewise, we are using NAA as a rapid, inexpensive
technique for determining the biodistribution of therapeutic gold nanoparticle systems.
Results from both applications will be presented.
NUCL 34
Thermochemistry of actinide and lanthanide fluorides in molten salts
Thomas Fanghänel, [email protected], M. Beilmann, O. Beneš,
R.J.M. Konings.European Commission, JRC, Institute for Transuranium Elements,
Karlsruhe, Germany
The thermochemistry of actinide and lanthanide trifluorides is of particular interest for
the Molten Salt Reactor. The design and safety assessment of this reactor of the fourth
generation requires a thorough knowledge of the phase diagrams of the fuel (UF 4/UF3),
the fertile phase (ThF4), the solvent (LiF-BeF2, LiF-NaF, LiF-CaF2, …) and the fission
products (CsF, LnF3, …). We have been studying the relevant binary and ternary phase
diagrams by experimental and so-called CALPHAD modelling, and an overview will be
given in this presentation.
An important aspect of the experimental efforts is the availability of highly pure
chemicals. Special attention has been given to the purification of the actinide
tetrahalides, as the available products were found to contain significant amounts of
oxide impurity. The purification was performed by controlled reaction with NH3(HF)2.
Phase diagrams of a variety of systems have been studied, complementing the
available literature, and some examples will be presented. Special tools for the thermal
analysis equipment have been developed for this work to deal with the corrosive molten
materials. Our work of the binary LiF-UF3 and NaF-UF3 has resolved discrepancies in
the literature by consideration of the (partial) thermal decomposition of the UF 3. New
results have been obtained for the CaF2-ThF4 binary system.
The experimental results have been assessed according to the CALPHAD method and
combined with assessments of other binary systems reported in literature, a complete
description of multi-component, multi-phase system LiF-NaF-BeF2-ThF4-UF4-UF3 and
LiF-CaF2-ThF4-UF4 has been achieved. Examples will be given how to apply the
assessed data to evaluate safety related properties of the fuel.
NUCL 35
Role of actinide chemistry in reducing global threats
Carol J. Burns, [email protected]. Chemistry Division, Los Alamos National Laboratory, Los
Alamos, NM 87545, United States
The management of nuclear and radiological materials worldwide challenges our
abilities to detect, measure, and characterize actinides and other radionuclides. These
efforts also pose new challenges in our ability to predict their behavior in processes and
in the environment. These applications now benefit from the history of fundamental
developments in actinide and radiochemistry, as well as from current research in these
fields. Long term technical challenges in radioanalytical measurements and actinide
chemistry will be presented, and examples will be presented of ongoing LANL work
designed to address these challenges.
NUCL 36
Applications of time-dependent density functional theory to ligand K-edge
spectroscopy
Jason M. Keith, [email protected], Richard L. Martin, Enrique R. Batista. Theoretical
Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States
In recent years time-dependent density functional theory has become a powerful tool in
the elucidation of electronic spectra. At LANL we have employed these techniques in
collaboration with our experimental colleagues in an effort to understand the nature of
bonding interactions in transition metal and lanthanide/actinide complexes. Here a
general overview of the theoretical techniques used will be presented along with specific
examples where tddft was vital in elucidating the complex 5f and 6d contributions in
ligand K-edge spectra of Actinide complexes.
NUCL 37
Nuclear and radiochemistry summer schools
Paul F Mantica, [email protected]. Department of Chemistry and NSCL, Michigan
State University, East Lansing, MI 48824, United States
The Nuclear and Radiochemistry Summer Schools program was initiated in 1984 at San
Jose State University and expanded to a second site at Brookhaven National
Laboratory in 1989. The program is sponsored by the NUCL Division of the ACS with
funding from the U.S. Department of Energy. More than 500 undergraduate students
have participated in the program, which serves as a pipeline to enhance the nuclear and
radiochemistry workforce at national laboratories and universities. I will give an overview
of the Summer Schools, with emphasis on the important role Dr. Lester Morss played as
a strong advocate for the program within the NUCL division and the Department of
Energy, Office of Basic Energy Sciences.
NUCL 38
Application of microcalorimetry for thermodynamic studies of weak actinide
complexes
Linfeng Rao1, [email protected], Plinio Di Bernardo2, PierLuigi Zanonato2, Arturo
Bismondo3, Francesco Endrizzi2. (1) Lawrence Berkeley National Laboratory, Berkeley,
CA 94720, United States (2) University of Padova, Padova, Italy (3) Istituto di Chimica
Inorganica e delle Superfici del CNR, Padova, Italy
Microcalorimetric titrations were performed to study interactions between actinide
cations and weakly-binding ligands (e.g., nitrate) in aqueous solutions. The data were
interpreted as the formation of weak inner-sphere Th(NO3)3+ complex in aqueous
solutions at 25 °C and an ionic strength of 1 mol dm-3 (NaClO4). The nitrate anion
probably coordinates with Th4+ in a bidentate mode, similar to that in the corresponding
ThAc3+ complex. The complexation reaction is endothermic and entropy driven. As the
small and positive enthalpy of complexation for ThNO3+ (5.2 kJ mol-1) suggests, the
effect of temperature on the complexation of Th4+ with nitrate is slightly enhanced at
higher temperatures.
This work was supported by the Director, Office of Science, Office of Basic Energy
Sciences of the U.S. DOE under Contract No. DE-AC02-05CH11231 at the Lawrence
Berkeley National Laboratory.
NUCL 39
Developing the next generation thorium iodide starting materials
Nicholas E Travia, [email protected], Marisa J Monreal, Brian L Scott, Jaqueline L
Kiplinger. Los Alamos National Laboratory, Los Alamos, NM 87544, United States
Coordination chemistry of the early actinides (Th-Pu) continues to gain wide interest as
new and unique reaction chemistry promoted by these elements emerges. We aim to
develop new anhydrous starting materials for thorium chemistry and fuel cell research.
Historically, the Lewis base adduct ThI4(THF)4, synthesized from thorium metal and
iodine has been the reagent of choice for thorium iodide chemistry. However, thorium
metal is no longer widely available and ThI4(THF)4 undergoes rapid metal-mediated
THF ring-opening under mild conditions. The resulting product, ThI3[O(CH2)4I](THF)3, is
the first structurally characterized example of a ring-opened THF ligand on thorium. To
avoid the ring-opening reaction, we prepared the tetraiodide complex, ThI 4(DME)2 (DME
= 1,2-dimethoxyethane) from the reaction of ThCl4(DME)2 and Me3Si-I. ThI4(DME)2 can
be used to make thorium complexes that are inaccessible from ThI 4(THF)4. This new
route to ThI4(DME)2 not only bypasses the use of thorium metal but greatly enhances
access to thorium iodide chemistry.
NUCL 40
Curium contamination and decorporation: Mechanistic insights
Rebecca J Abergel, [email protected], Manuel Sturzbecher-Hoehne, Christophe
Goujon, Birgitta Kullgren, Erin Jarvis. Chemical Sciences Division, Lawrence Berkeley
National Laboratory, Berkeley, CA 94720, United States
Despite the general knowledge that actinides pose great hazards for humans and can
strongly bind to natural macromolecules, limited research has been directed to the
characterization of transuranic actinide coordination chemistry in environmentally and
biologically relevant species. Our approach uses the specific photophysical properties of
trivalent actinides to study their selective binding and recognition by natural and
synthetic ligands. The photophysics and solution thermodynamic behavior of Cm(III)
complexes formed with the protein transferrin and selected hydroxypyridonate chelating
agents were investigated. The specific interactions between the metal ion and these
ligands were then correlated to the in vivo decorporation capabilities of the chelating
agents after curium contamination.
Such studies have important implications for the use of spectroscopic methods to
predict the speciation of actinides in biological systems and to exploit the fundamental
coordination chemistry properties of actinide-specific ligands for the development of
new actinide sequestering agents and separation technologies.
NUCL 41
Role of actinide redox chemistry and thermodynamics in repository science
Donald T Reed, [email protected] and Environmental Sciences, Los Alamos
National Laboratory, Carlsbad, NM 88220, United States
Actinide redox chemistry and the associated thermodynamics of stable actinide phases
are critical factors in establishing the concentration of actinides in a nuclear waste
repository. It is well known that the solubility of reduced actinides (III and IV oxidation
states) is significantly lower than oxidized forms (V and/or VI). In this context,
understanding the interactions of reduced metals and microbiological processes with
actinides is very important to fully evaluate the conditions that will lead to lower-valent
oxidation states for the actinides.
Recent evidence for the predominant speciation of multivalent actinides under the highly
reduced conditions predicted for most repository concepts will be presented.
Agreements and disagreements between laboratory studies and predicted
thermodynamic results will be discussed. A basic understanding of the thermodynamics
of key actinide phases remain a key and important driver in nuclear repository design
and approach.
NUCL 42
Speciation of Technetium-99 in the presence of nanometer-sized metal oxides
Lynn C. Francesconi1, [email protected], Benjamin P. Burton-Pye1, Ivana
Radivojevic1, Donna McGregor1, Ghada Al Kadamany1, Israel M. Mbomekalle1, Eric
Weiss2, Wayne W. Lukens3, Xavier Lopez4, Josep M. Poblet4, Silvia S. Jurisson2. (1)
Chemistry, Hunter College of the City University of New York, New York City, New York
10065, United States (2) University of Missouri, Department of Chemistry, Columbia,
Missouri 65211, United States (3) Chemical Sciences Division, The Glenn T. Seaborg
Center, E.O. Lawrence Berkeley National Laboratory, Berkeley, California 94720,
United States (4) Departament de Quimica Fisica, Universitat Rovira i Virgili,
Tarragona, Spain
The isotope technetium-99 (99Tc ,βmax: 293.7 keV, half-life: 2.1 x 105 years) is a major
product of U-235 fission and is present in spent fuel as well as in the radioactive waste
stored in underground tanks at Hanford and Savannah River. The complex redox
activity of 99Tc poses a problem for closing the fuel cycle, remediation of waste tanks
and immobilization of 99Tc found in the environment. Polyoxometalates (POMs),
nanometer-sized metal oxide clusters, and polyphosphates incorporate 99Tc into their
vacancies and stabilize specific oxidation states depending on the coordination
environment of the metal oxide vacancies or defects. Studies that include X-ray
crystallography, X-ray Absorption Spectroscopy, electrochemistry, multinuclear NMR in
combination with theoretical methods, result in identification of features of POM and
polyphosphate binding sites that enhance stability of low valent 99Tc. POMs,
themselves, can be photoactivated in the presence of 2-propanol to transfer electrons to
99
TcO4- and stabilize the low valent 99Tc.
NUCL 43
Development of bioconjugation reagents for labeling biomolecules with astatine211
D. Scott Wilbur, [email protected], Donald K. Hamlin, Ming-Kuan Chyan, Ethan R.
Balkin. Department of Radiation Oncology, University of Washington, Seattle, WA
98105, United States
Astatine-211 is of high interest in development of targeted therapeutic
radiopharmaceuticals. However, in vivo instability of astatinated biomolecules has been
problematic. We have evaluated a number of bioconjugation reagents designed to
circumvent the in vivo instability, including several that contain aromatic boron cage
moieties. Those studies demonstrated that reagents containing a closo-decaborate(2-)
moiety provide biomolecule labeling that is stable to in vivo deastatination. A number of
bioconjugation reagents containing the closo-decaborate(2-) moiety have been
developed to prepare monoclonal antibody (mAb) conjugates. Importantly, those
conjugates can be astatinated directly in high yields. Unfortunately, the unique nature of
the dianionic decaborate(2-) moiety can also introduce undesirable in vivo
characteristics. Thus, modifications in the reagents have been made to keep them from
localizing in kidneys or liver, and to change the pharmacokinetics of the labeled
biomolecule. Examples of the development and applications of several At-211 labeling
reagents will be given in this presentation.
NUCL 44
Production of 72Se for use in a 72Se/72As generator for PET imaging
Beau Ballard1, [email protected], Don Wycoff2, Silvia Jurisson2, Eva Birnbaum1, Kevin
John1, Cathy Cutler3, Francios M Nortier1, Wayne A Taylor1, Michael Fassbender1. (1)
Department of Chemistry, Los Alamos National Laboratory, Los Alamos, New Mexico
87545, United States (2) Chemistry, University of Missouri, Columbia, Missouri 65211,
United States (3) Missouri Research Reactor Center, University of Missouri, Columbia,
Missouri 65211, United States
Radionuclide generators constitute a convenient tool for applications in nuclear
medicine. Arsenic-72 (half life 26 h) is a positron emitting radionuclide for PET imaging
is produced as a daughter of 72Se (half life 8.5 d). The 26 hour half life of 72As is short
enough to limit the radiation dose delivered to the patient while long enough to allow for
imaging of slower biological processes. A 72Se/72As generator system would be suitable
for hospital on-site utilization. No portable 72Se/72As generator system is available on
the market for convenient, repeated 72As elution at the point of care (“milking”).
Radionuclide generator principles for 72Se/72As have been proposed in the literature,
including repeated distillation of “grown-in” 72AsCl3 from carrier added 72Se stock
solutions, electroplating of 72Se as Cu2Se on Cu backings, and solid phase extraction of
72
Se. We describe a 72Se/72As generator system analogous to a well-developed
commercial 82Sr/82Rb generator system.
Production of the parent 72Se via 90 MeV proton bombardment of a natural NaBr target
has been successfully demonstrated at the Los Alamos National Laboratory's Isotope
Production Facility (LANL-IPF). The 72Se from proton irradiated NaBr targets was
chemically recovered at the LANL Hot Cell Facility in good yield (94%). Good
agreement of theoretical thick yields and experimental results were obtained. Batch
recovery of 72As via liquid-liquid extraction resulted in a 76% yield, with minimal
breakthrough of the 72Se parent (0.9%). Moreover, feasibility testing of a solid phase
generator system will be discussed. (LA-UR 11-05941)
NUCL 45
Design criteria for targeted molecules: Muscarinic cholinergic systems biology
William C Eckelman, [email protected]. Molecular Tracer LLC, United States
Receptor-binding radiotracer design has evolved from a goal of developing high affinity
compounds that give high target to non-target ratios to compounds of slightly lower
affinity that reach either steady state after bolus injection or equilibrium after infusion.
The former approach is best suited for targeting proteins for occupancy studies or for
radiotherapy using beta emitting radionuclides where high affinity, high uptake, and long
retention are advantages; advantages of the latter approach are increased sensitivity to
target protein changes, less dependence on flow and permeability, and the ability to
measure endogenous neurotransmitter concentration. These two approaches are
exemplified by the development of 3-R-quinuclidinyl 4-S-[123I]iodobenzilate ( RS 4[123I]IQNB) and 3-(3-[18F]fluoranylpropylsulfanyl)-4-(1-methyl-3,6-dihydro-2H-pyridin-5yl)-1,2,5-thiadiazole ([18F]FP-TZTP).
NUCL 46
Fifty plus years of technetium (2.5 x 10-4 of the half life of Tc-99)
Lynn C Francesconi, [email protected]. Department of Chemistry, Hunter
College, New York, New York 10065, United States
Technetium chemistry is complicated. The 2012 recipient of the Seaborg Award,
Professor Silvia Jurisson, was one of the first inorganic chemists to elucidate the
chemistry of this fascinating transition metal starting as a graduate student. Her
inspirational work elucidated the coordination chemistry and provided understanding of
the redox chemistry of Tc-99m drugs that are clinically used. The presenter of this
seminar and Professor Jurisson have a combined fifty plus years working with
technetium. First, working together at Squibb, we identified and developed Tc-99m
complexes for diagnostic imaging. Subsequently we took independent paths that were
connected in a quest to understand the complex redox chemistry of Technetium and its
third row congener, Rhenium. These studies have applications in identification of
materials for stabilization of Tc-99 that is a byproduct of uranium fission and found in the
environment. Also, this work finds application in identifying ligands for stabilization of
Rhenium-186 and Rhenium-188 for radiotherapy applications. Case studies in
technetium-99m drug design and in understanding the complex chemistry of
technetium-99 incorporated into redox active metal oxide materials will be discussed in
this seminar as inspired by Professor Jurisson.
NUCL 47
Role of radiochemistry in studying the interrelationship between Auxin signaling
and plant root development
Richard A Ferrieri, [email protected]. Medical Department, Brookhaven National
Laboratory, Upton, New York 11973, United States
Lateral root formation is an agronomic trait in plant architecture that can determine crop
productivity and stress adaptability and is tightly regulated by intrinsic developmental
cues in plants associated with hormones like auxin. In recent studies, we found that
maize plants stressed through damage by Diabrotica virgifera virgifera (western corn
rootworm) often exhibited accelerated lateral root growth. This correlated with elevated
endogenous auxin, and with elevated expression of SAUR2, an auxin response gene.
To investigate what tissues contributed to this auxin pool we radiolabeled the hormone,
as 11C-indole-3-acetic acid, and radiolabeled its biosynthetic precursors, 11C-indole-3acetonitrile and 11C-indole-3-acetamide as a way to measure the rate of hormone
production. We found that damaged root production rates exceeded those of
undamaged roots, as well as those of leaves. We conclude that local root contribution to
the hormone pool was most important to the plant's adaptability for survival. This
research was supported by DOE-OBER.
NUCL 48
Fiber-based system for imaging tumor margins with Cerenkov Luminescence
Hongguang Liu1, Colin M Carpenter2, Han Jiang1, Guillem Pratx2, Conroy Sun2, Michael
P Buchin4, Sanjiv S Gambhir1,3, Lei Xing2, Zhen Cheng1, [email protected]. (1)
Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X
Program, Canary Center at Stanford for Cancer Early Detection, Stanford University,
Palo Alto, California 94305, United States (2) Department of Radiation Oncology,
Stanford University, Palo Alto, California 94304, United States (3) Department of
Bioengineering and Materials Science & Engineering, Stanford University, California
94305, United States (4) Stanford Photonics, Inc, Palo Alto, California 94303, United
States
Objective: Cerenkov Luminescence Imaging (CLI) has been introduced to be an
emerging new molecular imaging modality for advantages such as relatively
inexpensive, easy-to-use and high throughput. CLI is evaluated for its potential to
enable molecular image-guided surgery. In this study, we investigate the feasibility of
Cerenkov Luminescence Endoscopy (CLE) using newly developed fiber-based
Cerenkov imaging system to indicate the presence of tumor tissue.
Methods: An optical fiber bundle was coupled to a sensitive optical camera. The
sensitivity of the customized system was determined by imaging [ 18F]FDG in a black
well-plate in a dark-box. The resolution of Cerenkov endoscopy is compared to whitelight imaging by imaging a commercial SPECT phantom filled with [ 18F]FDG. Finally,
mice bearing C6 glioma tumors were injected intravenously to determine imaging
feasibility in tissue. Before and after surgical removal of the tumors, CLI was performed
on the mice using the fiber-based imaging system and compared to a commercial
optical imaging system.
Results: Sensitivity of this prototype was found to be ~ 37 KBq (1 µCi). The three
smallest sets of cylindrical holes in the SPECT phantom were identifiable via this
system, demonstrating resolution of this system to be better than 1.2 mm. Finally, the in
vivo tumor imaging study demonstrated the feasibility of using CLI to guide the resection
of tumor tissues.
Conclusions: This study explored the feasibility of using fiber-based CLE for the
detection of tumor tissue in vivo for guided surgery. With further improvements of more
sensitive instrumentation, it is expected to bring CLE technique into the clinical
applications in the near future.
NUCL 49
Positron emission tomography (PET) imaging with metal radionuclides: From
small molecules to nanoparticles
Michael J. Welch, [email protected], Yongjian Liu. Department of Radiology,
Division of Radiological Sciences, Washington University School of Medicine, St. Louis,
MO 63110, United States
The use of PET in clinical medicine has increased rapidly over the past decade. The
agent utilized in most clinical studies is fluorine-18-2-fluoro-deoxyglucose, however,
much development work is being carried out on agents labeled with metal radionuclides.
Many agents have been labeled with copper-64 which has a 12.7 half-life and decays
partially by positron emission. Many molecules have been labeled with copper-64, these
include copper-ATSM for imaging hypoxic tissue, several peptides and antibodies for
labeling tumor receptors and antigens, as well as nanoparticles for various applications.
Examples of the development of agents in these areas as well as the translation to
clinical studies will be discussed.
NUCL 50
Quantum spin liquid
Daniel Nocera, [email protected]. Department of Chemistry, MIT, Cambridge, MA
02139, United States
A new phase of matter: the quantum spin liquid will be presented. The introduction of
copper 2+ ions gives rise to a multidimensional ground state that cannot order down to
temperatures of 30 milliK. The implications of this material with regard to high
temperature superconductivity will be discussed.
NUCL 51
First circularly polarized luminescence spectrum of an actinide
Christopher M. Andolina1, Ga-lai Law1, Jide Xu1, Vinh Luu3, Philip X. Rutkowski2, Gilles
Muller3, David K. Shuh2, John K. Gibson2, Kenneth N. Raymond1,2,
[email protected]. (1) Department of Chemistry, University of California,
Berkeley, Berkeley, CA 94720-1460, United States (2) Chemical Sciences Division,
Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States (3)
Department of Chemistry, San Jose State University, San Jose, CA 95192, United
States
Circularly polarized luminescence (CPL) is a rarely used spectroscopy, that
discriminates between luminescent chiral complexes. Using several different chiral
chelating ligands, the world's first actinide Circularly Polarized Luminescence (CPL)
spectra with curium (III) complexes are reported. This provides a new tool to probe the
chemical and bonding differences between the 4f and 5f elements. We thank Lester
Morss for his contributions to this field.
NUCL 52
Carbon dioxide coordination, activation, and functionalization at reactive uranium
complexes
Karsten Meyer, [email protected], Suzanne C Bart, Oanh P Lam,
Stephan Zuend. Department of Chemistry and Pharmacy, Friedrich-Alexander
University Erlangen-Nürnberg, Erlangen, Germany
The tris-aryloxide triazacyclononane ligand, (t-BuArO)3tacn3–, and its sterically more
demanding derivatives have provided access to reactive coordination compounds of
uranium in oxidation states III, IV, V, and VI in custom-tailored ligand environments.
These complexes display a pronounced reactivity towards small molecules of biological
and industrial relevance. Reactions are presented that result in carbon dioxide
coordination, activation, splitting, and functionalization. It is shown that chargeseparated complexes are particularly reactive species that often lead to unprecedented
chemistry. Newly developed chelators and their exceedingly reactive U complexes are
introduced and an outlook into their small molecule activation chemistry is given.
NUCL 53
Evaluating orbital mixing in actinide–oxygen and actinide-carbon bonds using
ligand K–edge X-ray absorption spectroscopy
Stefan G Minasian1,2, [email protected], Jason M Keith2, Enrique R Batista2, Kevin S
Boland2, Joseph A Bradley4, David L Clark2, Steven D. Conradson2, Scott R Daly2,
Stosh A Kozimor2, Wayne W Lukens1, Richard L Martin2, David K Shuh1, Tolek
Tyliszczak1, Gregory L Wagner2, Ping Yang3. (1) Division of Chemical Sciences,
Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States (2)
Division of Chemistry, Los Alamos National Laboratory, Los Alamos, NM 87545, United
States (3) W.R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest
National Laboratory, Richland, WA 99352, United States (4) Division of Physical and
Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA 94550, United
States
The development of many essential nuclear technologies requires a comprehensive
grasp of the electronic ground and valence states of actinide (An) bonding interactions.
Ligand K-edge X-ray absorption spectroscopy (XAS) has been employed successfully
to probe valence states in materials containing M–Cl and M–S bonds, however, this
technique remains challenging at the K-edge for light atoms. We have employed a
combination of XAS and hybrid density functional theory (DFT) for molecular systems
containing interactions between actinide elements and carbon or oxygen-based ligands.
Actinyl ions, AnO22+, and the actinocenes, (C8H8)2An, were chosen for these
measurements because they have been foundational to modern theories of actinide
electronic structure. An ongoing collaboration with theorists will tie experimental trends
in An–C and An–O orbital mixing to changes valence orbital energies. Implications for
using orbital mixing to control the physical properties of An molecules and materials are
also considered.
NUCL 54
Time-resolved self-assembly of a Fullerene-topology core-shell cluster containing
68 uranyl polyhedra
Jie Qiu1, [email protected], Jie Ling1, Audrey Sui1, Jennifer E.S. Szymanowski1, Antonio
Simonetti1, Peter C. Burns1,2. (1) Department of Civil Engineering and Geological
Sciences, University of Notre Dame, Notre Dame, IN 46556, United States (2)
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN
46556, United States
Polyoxometalate clusters based on transition metals are structurally diverse and have
been intensely investigated. Normally, they are synthesized in one-pot reactions.
However, the details of their self-assembly mechanisms in reactions remain poorly
understood. In this study, we investigated the formation processes of a uraniumperoxide cluster {U1⊂U28⊂U40R} with a core-shell structure using time-resolved smallangle X-ray scattering (SAXS) and electrospary ionization mass spectrometry (ESI-MS)
techniques. The 'core' of {U1⊂U28⊂U40R} is a cage cluster built from 28 uranyl
polyhedra. A partially occupied U site is at its center. The 'shell' is a ring consisting of 40
uranyl polyhedra linked into five-membered rings and 16 nitrate groups. Topological
pentagons in the cage and ring are aligned, and their corresponding rings of uranyl
bipyramids are linked through K cations. Both SAXS and ESI-MS results demonstrate
that the cage cluster forms in solution within an hour, whereas the ring forms after more
than several days.
NUCL 55
Synthesis of uranyl disulfide: From monomer to cage clusters
Zhehui Weng, [email protected], Peter C. Burns. Department of Civil Engineering and
Geological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United
States
The compound Na8[(UO2)(S2)3]2(CH3OH)15(H2O) was synthesized at room temperature
in an oxygen-free environment and was characterized IR and UV-vis spectra. Single
crystal X-ray diffraction reveals this uranyl disulfide monomer contains a rare example
of the [(UO2)(S2)3] complex in which a uranyl ion is coordinated by three disulfide groups
that are each bidentate to the uranyl ion. Comparison has been made between the
possible linkage of these units to form nano-scale cage clusters analogous and those
formed from uranyl peroxo polyhedra, which might support the hypothesis of the
synthesis of cage nanoclusters based on uranyl sulfide.
NUCL 56
Protein-based multi-stage actinide separations
Mark P. Jensen1, [email protected], Baikuntha P. Aryal1,2, Drew Gorman-Lewis1, Paul
G. Rickert1, John V. Muntean1, L. Soderholm1, Tatjana Paunesku3, Gayle E.
Woloschak3, Stefan Vogt4, Barry Lai4, Soenke Seifert4. (1) Chemical Sciences and
Engineering Division, Argonne National Laboratory, Argonne, IL 60439, United
States (2) Department of Chemistry, University of Chicago, Chicago, IL 60637, United
States (3) Departments of Radiation Oncology and Radiology, Northwestern University,
Chicago, IL 60611, United States (4) X-ray Science Division, Argonne National
Laboratory, Argonne, IL 60439, United States
Most ligand design approaches to actinide separations focus on optimizing the metalligand bonding to achieve selectivity for the target metal ion in a single separation stage.
In living systems, nature sometimes takes a completely different approach to controlling
and separating metal ions, resorting to undersaturated metal binding sites and multistage separations. Multi-stage separations of plutonium based on biomacromolecules
can behave differently than common actinide separations. The thermodynamics of the
metal-ligand bonds formed in these complexes need not drive this separation. Instead,
the plutonium(IV) separation is based on the influence of the metal ions on the
conformation of the complex and the subsequent interaction between the metal
complexes and receptor proteins. These interactions take place on length scales that
are much longer than the actinide-ligand bonds in these complexes.
Work supported by the U.S. Department of Energy, Office of Basic Energy Sciences
under contract number DE-AC02-06CH11357.
NUCL 57
Tribute to Lester Morss: Americium redox potentials and other interactions
David E. Hobart, [email protected]. Chemistry Division, Los Alamos National
Laboratory, Los Alamos, NM 875445, United States
While attending graduate school at the University of Tennessee, Knoxville I had the
unique opportunity of working at the Transuranium Research Laboratory (TRL) at Oak
Ridge National Laboratory. The TRL was a focal point of actinide science attracting
notable researchers from around the world. Among these was Dr. Lester Morss whom I
met there when he was investigating americium calorimetry. He later queried me about
my work in generating americium(IV) in carbonate solution. My back-calculated
standard potential for the Am(IV/III) couple derived from electrochemistry agreed with
that of Morss' calorimetry work. Over the next thirty years we collaborated on various
committees and workshops and most recently on the publication of The Chemistry of
the Actinide and Transactinide Elements. Lester has always provided encouragement
and support and offered professional development opportunities that I could not refuse
and I look forward to additional valuable collaborations.
NUCL 58
Determination of electronic structure in uranyl salts by nuclear magnetic
resonance spectroscopy
Herman Cho, [email protected], Wibe A. DeJong, Chuck Z Soderquist.Pacific
Northwest National Laboratory, Richland, WA 99352, United States
Methods and instrumentation have been developed at the Pacific Northwest National
Laboratory to analyze actinide solids by modern time-domain nuclear magnetic
resonance (NMR) spectroscopy. This approach may be used to measure shielding and
electric field gradient (EFG) tensors, as illustrated by recent 17O NMR studies in uranyl
(UO22+) solids.1 In conjunction with relativistic density functional calculations, NMR
determinations of these key electronic parameters greatly enhances understanding of
the nature of covalent bonding in actinide oxides and clarifies the origins of the complex
magnetic behavior of these systems.
1. H. Cho, W. A. de Jong, and C. Z. Soderquist, J. Chem. Phys., 132 , 109901 (2010).
NUCL 59
Unique advantages of organometallic supporting ligands for uranium complexes
Paula L Diaconescu, [email protected]. Department of Chemistry & Biochemistry,
University of California, Los Angeles, Los Angeles, California 90024, United States
Ancillary ligand design in organometallic chemistry is drawing increasingly on inducing
ligand participation in reactions of the metal. Chelating ferrocene diamides possess
unique electronic characteristics that make them especially versatile in supporting a
wide range of reactivity behaviors for the resulting metal complexes. When combined to
the unique properties of uranium, new avenues can be opened. Oxidation of
uranium(IV) bis(1,1'-diamidoferrocene) complexes gives products that are best
described as mixed valence bisferrocenes, in which uranium mediates the electronic
communication. The characterization of these complexes and comparisons with nonactinide analogues will be presented.
NUCL 60
Remarkable variability in 5f and 6d orbital contributions to metal-oxygen bonding
in actinyl ions from U through Cm
David L Clark1, [email protected], Steven D Conradson1, Jun Li2, Mary P Neu1,
Wolfgang H Runde1, Brian L Scott1. (1) Los Alamos National Laboratory, Los Alamos,
NM 87545, United States (2) Department of Chemistry, Tsinghua University, Beijing,
China
The light actinide elements (U, Np, Pu, and Am) in their hexavalent oxidation states
form a wide variety of complexes based on the linear, dioxo (actinyl) cations, AnO 22+.
These ions are remarkably stable, having strong covalently bonded O=An=O ions.
Vibrational spectroscopy shows conclusively that the AnO22+ ion exists as a
symmetrical, linear group with a regular decrease in An=O bond strength with
increasing atomic number from uranium through americium. For curium, there is no
conclusive evidence for the existence of the actinyl ion. We report single crystal x-ray
diffraction, and solution EXAFS measurements that reveal a remarkable shortening, and
then lengthening of the An=O bond along the series, U, Np, Pu, Am. Theoretical studies
reveal that the origin of this trend can be traced to changing contributions from 5f and
6d atomic orbitals in the O=An=O bonding core, providing additional insights on the lack
of a Cm analog.
NUCL 61
Purification of actinium-227 from Ac-Be neutron sources for medical isotope
production
Matthew D Gott1,2, [email protected], Rose A Boll2, Spenser R Walsh2, Kayla R
Kennedy2. (1) Department of Chemistry, University of Missouri-Columbia, Columbia,
Missouri 65211, United States (2) Fuel Cycle and Isotope Division, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37831, United States
Medical therapies, using alpha-emitting isotopes, have shown promising results and
significant potential for treatment of cancer thus the demand for these isotopes is rapidly
increasing. One isotope of interest is the alpha emitter Ra-223 (t1/2 = 11.4 days) which is
being used with good success for pain palliation in bone cancer patients. The only
viable source of Ra-223 is from the beta decay of relatively long-lived Ac-227 (t1/2 = 21.8
years) to a shorter-lived Th-227 (t1/2 = 18.7 days) which alpha decays to Ra-223. A
significant quantity of Ac-227 was in inventory at Oak Ridge National Laboratory in the
form of stainless steel-encapsulated actinium-beryllium neutron sources, which no
longer had an identified mission. The stainless steel encapsulations were mechanically
breached, the Ac-Be pellets were dissolved using nitric acid, and the Ac-227 was
separated from the beryllium and other contaminants using anion and cation exchange
columns, including Eichrom DGA resin. The separation, purification, and quality
assurance data will be presented.
NUCL 62
Methods for the separation of Tc-99m from low specific activity Mo-99
Daniel R McAlister1, [email protected], E Philip Horwitz1, James T Harvey2. (1)
PG Research Foundation, Inc, Lisle, IL 60532, United States (2) Northstar Medical
Radioisotopes, Madison, WI 53703, United States
Technetium-99m is widely used in many diagnostic nuclear medicine procedures.
Typically, 99mTc is milked from a generator containing high specific activity molybdenum99 sorbed on a column of alumina. Historically, the 99Mo has been predominantly
produced by the fission of highly enriched uranium targets. However, due to shortages
resulting from reactor outages and the desire to move away from highly enriched
uranium (HEU) targets, alternative production methods for the production of 99Mo have
gained interest.
Alternative production methods for 99Mo include neutron irradiation of 98Mo enriched
targets, 98Mo(n,g)99Mo, and gamma irradiation of 100Mo enriched targets,
100
Mo(g,n)99Mo. Both of these alternative 99Mo production methods yield 99Mo of
considerably lower specific activity than production via HEU fission. Due to the relatively
high mass of Mo, efficient separation of 99mTc from this low specific activity 99Mo
requires chromatrographic systems which selectively retain 99mTc while rejecting 99Mo.
Flowsheets for the separation of 99mTc from low specific activity 99Mo and the
performance of these flowsheets using an automated chromatographic system will be
discussed.
NUCL 63
Rapid and sensitive LC-MS approach to quantify cold metal impurities in
radiometals to accurately determine effective specific activity
Dexing Zeng, [email protected], Carolyn J. Anderson. Department of Radiology,
University of Pittsburgh School of medicine, Pittsburgh, PA 15219, United States
Current methods for analysis of the purity of radiometals include the DOTA/TETA
titration and ion chromatography (IC). Titrations provide only the effective specific
activity and may suffer from inconsistent results depending on labeling conditions, while
IC is limited by sensitivity and requires the use of high concentrations and activities of
radiometals. To overcome these problems, a rapid and sensitive LC-MS approach using
both traditional and stable-isotope labeled agents was developed. 13C/2H-labeled and
traditional 12C/1H DOTA analogs were synthesized and chelated with a known
concentration of transition metals (including Fe(III), Ni(II), Cu(II) Co(II), Zn(II)) and 2-5
mCi of Cu-64, respectively. This mixture was analyzed by LC-MS, and data showed that
each metal ion in the Cu-64 solution can be quantified by comparing the MS peaks of
light (Cu-64 solution) and heavy (metal impurities) complexes. This approach appears
very promising for the rapid analysis of various radiometals, such as Ga-68 and Cu-64.
NUCL 64
Stability and biodistribution of a radiolabeled “small peptide selector” complex
Nebiat Sisay1, [email protected], George P Smith2, Cathy S Cutler3, Silvia S
Jurisson1,3. (1) Department of Chemistry, University of Missouri-Columbia, Columbia,
MO 65211, United States (2) Department of Biological Science, University of MissouriColumbia, Columbia, MO 65211, United States (3) University of Missouri Research
Reactor Center, Columbia, MO 65211, United States
A DOTA analog containing a weak Michael acceptor group (a maleimide group;
AmMABD) was utilized to covalently bind through a cysteine moiety to peptides that
could be fused to tumor-binding antibody. Tumor targeting antibodies, known for their
poor pharamcokinetics, are conjugated to the cysteine containing peptide and
administered prior to the radiolabeled DOTA analog and allowed to accumulate at the
tumor sites. A subsequent injection of radiolabeled DOTA analog with high affinity to the
cysteine containing peptide linked to the antibody allows in vivo targeting to the tumor.
Small peptides with high affinity for the metallated chelate (Ga- or Lu-AmMABD) are
selected from a random phage display library. The peptide selection process is
underway, however evaluation of the stability and biodistribution of radiolabeled 68Gaand 177Lu-AmMABD in vivo has been determined and shows the potential utility of this
method.
NUCL 65
Modeling rhenium(V)-cyclized octreotide analogs using computational methods
Yawen Li1, [email protected], Carol A. Deakyne1, John E. Adams1, Silvia S.
Jurisson1, Michael R. Lewis2. (1) Department of Chemistry, University of MissouriColumbia, Columbia, MO 65211, United States (2) Department of Veterinary Medicine
and Surgery, University of Missouri-Columbia, Columbia, MO 65211, United States
Motivated by our interest in developing rhenium-186 and rhenium-188 based
therapeutic radiopharmaceuticals, the structural flexibility and chemical stability of
rhenium(V)-cyclized octreotide [DPhe-c(Cys-DPhe-DTrp-Lys-Thr-Cys)-Thr-(ol)]
analogues are being investigated using computational methods. An effort is underway
to derive Re(V) parameters that are applicable to the AMBER force field ff99 in order to
study Re(V) incorporated into peptide analogues. Quantum chemical methods are used
to compute relative energies, vibrational frequencies, rhenium binding energies and
charge distributions. So far, molecular dynamics simulations have been performed on
water solvated Tyr3-octreotate. A simulated annealing approach was employed to
search the conformational space thoroughly and reveal the structural flexibility of the
molecule. In addition, the study of the effect of the amino acid side chains on the
peptide backbone conformation suggested that the charged termini have shown much
larger influence on the backbone conformation than the side chains in the gas-phase
electronic structure calculations.
NUCL 66
Prostate specific membrane antigen targeted multifunctional gold nanoparticles
for prostate cancer therapy and radioimaging
Kinh-Luan (Lenny) Dao Dao, [email protected], Robert N Hanson. Chemistry and
Chemical Biology, Northeastern University, Boston, Ma 02115, United States
Early stage prostate cancer is usually treated with surgery and local radiation. This
treatment is often accompanied by adjuvant anti-hormonal (castration) therapy that
blocks the effects of testosterone in the prostate. However, anti-hormonal therapy
typically loses its effectiveness within 2-4 years as the prostate cancer becomes
castration resistant (CRPC). At that point aggressive chemotherapy must be used,
which produces undesirable side effects. A drug delivery system, such as
multifunctional nanoparticles, that can selectively target prostate cancer may effectively
eradicate prostate cancer cells, including those associated with recurrence and
resistance, would prolong the disease free interval for the patient, reduce morbidity, and
possibly eliminate the disease.
In this presentation, a strategy based on the design and synthesis of a multifunctional
gold nanoparticulate (mfAuNPs) drug delivery system that is prostate cancer specific
will be discussed. We have developed a convergent modular assembly approach to
prepare a series of individual components. For example, terminally functionalized azidotetraethylene glycol components, in which the terminal units were- a) prostate specific
membrane antigen (PSMA) ligands for targeting the prostate specific antigen (PSA)
membrane receptors overexpressed on prostate cancer cells; b) pH-sensitive
doxorubicin for inhibiting the cell proliferation c) a metal chelating moiety for 99Tclabeling, a tosylated precursor for 18F precursors, or a stannylated precursor for 123I. The
complementary lipoic acid components (AuNP binding) were prepared with a terminal
propargyl tetraethylene glycol moiety. Huisgen [3+2] “click” cyclo-addition chemistry
gives the final target system bearing the appropriate terminal groups.
Initial in vitro studies with the PSMA-targeted mfAuNPs demonstrated significant
selective uptake and localization properties in LnCaP and PC-3 prostate cancer cells.
DOD (W81XWH-10-1-0262) and DOE (DE-SC0001781)
NUCL 67
Synthesis of a 105Rh tetrathioether bombesin molecule for prostate cancer
therapy
Valerie N Carroll1, [email protected], Donald E Wycoff1, Gary L Sieckman2,
Timothy J Hoffman2, Silvia S Jurisson1. (1) Chemistry, University of Missouri Columbia,
Columbia, MO 65211, United States (2) Research Division, Harry S. Truman VA
Hospital, Columbia, MO 65201, United States
Rhodium-105 is an ideal candidate for radiotherapeutic applications. It is a moderate β emitter (0.566 MeV [70%], 0.248 MeV [19%], t½= 35.4 h) and is available in “no-carrieradded” concentrations. The aim of this project is to develop a tetrathioether bombesin
bioconjugate that when complexed with 105Rh (105Rh-S4-8Aoc-BBN) will useful for
targeted radiotherapy of prostate cancer. Bombesin peptide targets gastrin releasing
peptide (GRP) receptors, which have been shown to be over-expressed on the surface
of prostate cancer cells. Chelate synthesis, peptide coupling, radiolabeling and
potentially IC50 studies of the S4-8Aoc-BBN bioconjugate will be presented.
NUCL 68
Positron emission tomography imaging of colorectal cancer with
huA33 antibody
89
Zr-labeled
Brian M Zeglis, [email protected], Priya Mohindra, Steven M Larson, Jason S Lewis.
Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New
York 10065, United States
Humanized A33 (huA33) is a monoclonal antibody that targets the A33 antigen, a
transmembrane glycoprotein expressed in >95% of human colon adenocarcinomas.
The absence of the antigen from most non-cancerous tissues has made huA33 a
promising candidate for use in imaging applications, particularly PET. We have sought
to evaluate 89Zr-labeled huA33 as a PET imaging agent for A33 antigen-expressing
colorectal cancer xenografts. To this end, huA33 was modified with the chelator
desferrioxamine (DFO) via isothiocyanate linkage, labeled with 89Zr, and purified to yield
89
Zr-DFO-huA33 in high radiochemical purity, specific activity (4.5-5.0 mCi/mg), and
immunoreactivity (>88 ± 4%). Small animal PET imaging and acute biodistribution
experiments with nude mice bearing A33 antigen-expressing SW1222 colorectal cancer
xenografts revealed high specific uptake of the 89Zr-DFO-huA33 in the xenografts (56.7
± 7.8%ID/g and 70.9 ± 10.1%ID/g at 24 and 48 h, respectively) with low levels of uptake
in all non-target tissues.
NUCL 69
One-step 18F-labeling of marimastat, a clinically trialed drug, to image breast
cancer associated matrix metalloproteases in mice
David M. Perrin1, [email protected], Ying Li1, Richard Ting1, Curtis W. Harwig1,
Ulrich auf dem Keller3, Caroline L. Bellac3, Philipp F. Lange3, James A.H. Inkster2, Paul
Schaffer2, Michael J. Adam2, Thomas J. Ruth2, Francois Benard4, Christopher M.
Overall3. (1) Department of Chemistry, University of British Columbia, Vancouver, BC
V6T-1Z1, Canada (2) Department of Nuclear Medicine, Triumf, Vancouver, BC V6T2A3, Canada (3) Department of Biochemistry, University of British Columbia,
Vancouver, BC V6T-1Z3, Canada (4) Centre of Excellence for Functional Cancer
Imaging, BC Cancer, Vancouver, BC V5Z-1L3, Canada
Matrix metalloproteinases are important cancer markers which have been extensively
targted. Marimastat, a noncovalent MMP inhibitor, is a clinically trialed drug used to
treat breast cancer, by inhibiting cancer-associated MMPs. Herein, marimastat was
linked to an aryl boronic ester for single-step [18F]-aqueous fluoride capture and the
labeled product localized to the tumors, with labeling being blocked in control animals
first loaded with >10-fold excess unlabeled marimastat.
The advantages of this labeling include one-step post synthetic labeling at ambient
temperature, no need to dry the [18F]-fluoride, high radiochemical purity, and the
potential for tripling the specific activity of the fluoride used in labeling. Using 60 mCi in
low volumes marimastat attained specific activities of 0.16 and 0.39 Ci/µmol at time of
injection.
NUCL 70
Development of a dual mode (PET/fluorescence) tag for monitoring plantsignaling peptides
Patrick L Cavins1, [email protected], Timothy E Glass1, Xiuli Zhang2, Thomas P.
Quinn2, Francois Gabbai3. (1) Department of Chemistry, University of MissouriColumbia, Columbia, MO 65211, United States (2) Department of Biochemistry,
University of Missouri-Columbia, Columbia, MO 65211, United States (3) Department
of Chemistry, Texas A&M University, College Station, TX 77842, United States
Using a 1, 3, 5, 7, 8-pentamethylpyrromethene-boron difluoride (BODIPY) derivative
has been shown to be an efficient method for the capture of fluoride ions in organic
media. Furthermore, the synthetic versatility and the fluorescence properties of the
BODIPY core make it a suitable option for the synthesis of water soluble derivatives and
a dual mode tag. Recently, the ability of a DMAP substituted BODIPY core has been
shown to capture F18 in acetonitrile with excellent RCY and RCP. Work is currently
focused on developing a labeling synthon for plant signaling peptides in the form of an
8-carboxy phenone NHS ester.
NUCL 71
First air-stable, highly fluorescent primary phosphines and their potential
applications as precursors for new disease imaging agents
Lee J Higham, [email protected]. Department of Chemistry, Newcastle University,
Newcastle upon Tyne, Tyne and Wear NE1 7RU, United Kingdom
Primary phosphines have a reputation as being highly air-sensitive compounds,
however there are a handful of air-stable examples whose stability is as yet
unaccounted for.1 Our model based on DFT methodology rationalizes this stability to air
and shows it can also be extended to secondary and tertiary phosphines too. 2 This
allowed us to predict and prepare the first air-stable, highly fluorescent bodipy-based
primary phosphines,3 and here we present their synthesis, stability, photophysical
properties and potential applications as disease imaging agents.
1. M. Brynda, Coord. Chem. Rev., 2005, 249 , 2013-2034.
2. B. Stewart, A. Harriman and L. J. Higham, Organometallics, 2011, 30 , 5338-5343.
3. L. H. Davies, R. W. Harrington, W. Clegg and L. J. Higham, Manuscript in
preparation.
NUCL 72
New actinide aminodiboranates and borohydrides
Gregory S Girolami, [email protected], Scott R. Daly, Do Young Kim, Andrew C.
Dunbar. School of Chemical Sciences, University of Illinois at Urbana-Champaign,
Urbana, IL 61801, United States
Sodium N,N-dimethylaminodiboranate, Na(H3BNMe2BH3), is a new type of chelating
borohydride ligand that forms many interesting complexes with actinides and
lanthanides. Among these are Th(H3BNMe2BH3)4, in which the thorium center forms
bonds with fifteen hydrogen atoms; accordingly, this is the first example of a fifteencoordinate metal complex of any kind. Single crystal X-ray neutron diffraction studies,
as well as quantum chemical calculations will be described. Uranium forms the trivalent
complex U(H3BNMe2BH3)3, which has been crystallized as two different structural
isomers from pentane and toluene, respectively. It forms the Lewis base adducts
U(H3BNMe2BH3)3(thf), U(H3BNMe2BH3)3(dme), and U(H3BNMe2BH3)3(PMe3)2. We also
will describe recent results on the synthesis of thorium complexes of the borohydride,
including the first example of a sixteen coordinate metal complex of any kind.
NUCL 73
f-Element coordination chemistry with relevance to nuclear fuel cycle separation
challenges
Matthew B Jones1, [email protected], Andrew J Gaunt1, Trevor W Hayton3, Nikolas
Kaltsoyannis4, Kelly A Kluge5, Cora E MacBeth5, Iain May1, Sean D Reilly1, David D
Schnaars3, Brian L Scott2. (1) Chemistry Division, Los Alamos National Laboratory, Los
Alamos, NM 87544, United States (2) Materials Physics and Applications Division, Los
Alamos National Laboratory, Los Alamos, NM 87545, United States (3) Department of
Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA
93106, United States (4) Department of Chemistry, University College London, London,
London WC1H 0AJ, United Kingdom (5) Department of Chemistry, Emory University,
Atlanta, GA 30322, United States
Research into ligand complexation reactions with f-element cations is motivated by both
the desire to understand the electronic structure and bonding of these elements, as well
as to further develop the use of their complexes in applications such as nuclear fuel
cycles and radioactive waste remediation. Exploring the fundamental chemistry that
underpins a range of actinide separation strategies is vital to facilitate development and
implementation of fuel recycling and waste disposition/minimization options. For
example, soft donor extractants have attracted a lot of attention due to their ability to
selectively complex An(III) versus Ln(III) ions, a challenging separation as a result of the
chemical similarity of these ions. In order to probe the role that covalency plays in
effecting selectivity, we are studying structurally similar Ln(III) and An(III) complexes
featuring N, O, S and Se donor ligands. Bonding comparisons across the An(IV) series
are also considered. In particular, we incorporate transuranic molecules into our studies,
of which far less is known compared to the chemistry of the lanthanides or
thorium/uranium. The syntheses and characterization of these complexes, which
include β-ketoiminates, diselenophosphinates, and tri(amidato)amine ligands, will be
described. We will analyze for bonding differences that have implications for ligand
design in actinide separation technology.
NUCL 74
Theoretical studies of dithiophosphinate complexes in Am3+/Eu3+ separation
chemistry
Jason M Keith1, Scott R Daly2, Stosh A Kozimor2, Gordon D Jarvinen2, Andrew J
Gaunt2, Enrique R Batista1, [email protected]. (1) Theoretical Division, Los Alamos
National Laboratory, Los Alamos, NM 87545, United States (2) Chemistry Division, Los
Alamos National Laboratory, Los Alamos, NM 87545, United States
Minor actinides found in spent nuclear fuel, such as Am3+ and Cm3+, have isotopes with
substantial radioactive half-lives that generate significant amounts of heat, which is
detrimental to long-term waste storage. As a result, selective extraction of these
actinides from spent reactor fuel is currently of great interest. In addition to reducing the
radiotoxic lifetime and heat production of the remaining spent fuel, these minor actinides
can be remediated by subsequently transmutating them in burner-type reactors once
they have been separated. In solution, minor actinides have similar ionic radii and
properties as the trivalent lanthanides such as Eu3+, and these similarities make
selective extraction from lanthanide fission products found in spent fuel difficult.
Recently, Klaehn et al. developed a series of CF3-substituted diaryldithiophosphinic
acids that can be used to extract Am3+ in the presence of Eu3+, but the selectivity varies
dramatically (by factors of more than 500) with only slight modifications to the number
and position of the CF3 groups on the phenyl substituents.[i] That type of difference
lends itself to theoretical studies that can shed insight into the determining factors that
lead to Ln/An separations. We have used first-principle calculations to study compare
and contrast the coordinated species in solution in order to understand what leads to
the difference in affinities. These computational studies have lead us to proposing new
molecular extractants that will be used to verify the theoretical predictions.
[i] Klaehn, J.R.; Peterman, D.R.; Harrup, M.K.; Tillotson, R.D.; Luther, T.A.; Law, J.D.;
Daniels, L.M. Inorg. Chim. Acta 2008 , 361, 2522.
NUCL 75
Assembly mechanisms and properties of nanoscale uranyl peroxo cage clusters
Peter C Burns, [email protected]. Department of Civil Engineering and Geological
Sciences, Department of Chemistry and Biochemistry, University of Notre Dame, Notre
Dame, IN 46556-0767, United States
Uranyl peroxo polyhedra self-assemble into more than 70 nano-scale cage clusters.
This presentation will focus on their assembly mechanisms, as revealed by timeresolved electrospray ionization mass spectrometry and small-angle X-ray scattering
complemented by quantum chemical simulations. The behavior of uranyl peroxo cage
clusters in solution under varying conditions of ionic strength and pH will be examined
on the basis of dynamic light scattering experiments.
NUCL 76
Role of solvent organization and hydrophobicity upon Np(III) extraction from
water to pentane
Aurora E. Clark1, [email protected], Yasaman Ghadar1, Barbara L Mooney2, L. Rene
Corrales2. (1) Chemistry, Washington State University, Pullman, Wa 99164, United
States (2) Chemistry, University of Arizona, Tuscon, Az, United States
The extraction of trivalent actinides from complex mixtures of dissolved spent fuel is of
vital importance for potential recycling efforts and current remediation and storage
strategies of high level waste. While much effort has been dedicated toward empirical
strategies for optimizing extraction efficiency under a variety of conditions, the
underlying fundamental physical mechanisms of extraction are often uncertain and the
role of different physical forces upon extraction thermodynamics and kinetics are
understudied. Toward this end, we present the results of multiple endeavors, including
the development and application of a novel post-processing molecular dynamics
algorithm that is a more accurate way to determine solvent organization about solutes, a
detailed analysis of the hydrophobic interaction at organic:aqueous interfaces, and the
extraction thermochemistry of Np(III) complexes with acetylacetate as a model
extracting ligand. In combination, these data are beginning to reveal the complex but
tractable physical phenomena that influence extraction efficiency.
NUCL 77
From dreams of alkylidenes to basic actinide starting materials: Ten years with
Lester Morss and heavy element chemistry
Jaqueline L Kiplinger, [email protected]. Los Alamos National Laboratory, Los
Alamos, NM 87545, United States
Compared to transition metals, the organometallic chemistry of the actinides is relatively
unexplored. Over the years, under the auspices of the BES Heavy Element Chemistry
program, with Lester Morss as Program Director, our laboratory has successfully
utilized the bis(pentamethylcyclopentadienyl) platform to support both high- and lowvalent uranium complexes allowing the exploration of uranium in unusual oxidation
states, uranium-multiple bonds, reactions uniquely enabled by f-orbitals, and metalmetal communication. A brief history of personal publications and the influence that
Lester Morss has had on the research and the career of the speaker will be presented,
followed by a discussion of recent selected results. These will include our efforts
towards preparing a terminal uranium nitride complex and the development of the next
generation of starting materials for thorium and uranium chemistry.
NUCL 78
Evaluating the electronic structure of minor actinide extractants
Scott R. Daly, [email protected], Jason M Keith, Enrique R. Batista, Kevin S. Boland,
David L. Clark, Andrew J. Gaunt, Stosh A. Kozimor, Richard L. Martin, Brian L. Scott,
Gregory L. Wagner. Los Alamos National Laboratory, Los Alamos, NM 87544, United
States
Proliferation-resistant nuclear fuel cycles offer a means to responsibly manage
inventories of spent nuclear fuel and an opportunity to meet increasing global energy
demands without increasing anthropogenic CO2 emissions with respect to fossil fuel
combustion. One of the most significant chemical challenges facing the development of
this type of technology is associated with separating minor actinides from lanthanide
contaminates in spent nuclear fuel. Although this represents one of the most difficult
separations, it is well-established that certain “soft-donor” extractants are exceptional at
selectively extracting minor actinides in the presence of lanthanides. Despite significant
experimental and theoretical advances, the factors that contribute to this extraction
selectivity remain poorly understood. Often it is suggested that effective separations
result, in large part, from the special attributes associated with the ligand's electronic
structure, which leads to more covalent metal-ligand bonding with the minor actinides
vs. lanthanide elements. In this contribution, we will describe our preliminary efforts
evaluating how the electronic structure and bonding associated with the extracting
ligands leads to selectivity in minor actinide extraction chemistry.
NUCL 79
On the changing role of the 5f-electrons: Do we really understand it?
R. G. Haire, [email protected]. Oak Ridge National Laboratory, United States
As this symposium is a tribute to Lester Morss' career in actinide science, it is
appropriate to note that Lester was involved in multiple career roles: (1) as a professor
(Rutgers University); (2) as a scientist at Argonne National Laboratory; and (3) finally as
a DOE manager for actinide research before his retirement. Given his training under
Professor Cunningham at Berkeley University, he was interested in the nature of 5felectrons across the series. Since Seaborg's famous realization that the early actinides
were not a mirror image the lanthanides, scientists have focused on these 5f-electrons
and concepts have evolved on the role these 5f electrons do play across the actinide
series. Discussed here will be quick snapshots for some of these changing concepts
and recent information that may require some additional evaluations about the 5felectron roles.
NUCL 80
Varying the venerable cyclopentadienyl ligand system to explore new
organoactinide chemistry
William J Evans, [email protected]. Department of Chemistry, University of California,
Irvine, Irvine, CA 92697, United States
Although cyclopentadienyl ligands are the oldest and most heavily studied ancillary
ligands in organometallic actinide chemistry, they continue to provide new opportunities
to develop the reaction chemistry of the heaviest elements. Since </del>(C5Me5)1</del>has proven to be an exceptionally effective cyclopentadienyl group, relatively less
effort has been given to other types of cyclopentadienyl ligands. Several examples of
new organoactinide reactions will be described in which variations in the substitution
pattern of the cyclopentadienyl ring are critical to the success of the reaction. A
comparison of the reactivity of (C5Me5)3U, (C5Me4SiMe3)3U, and (C5Me4H)3U with NO
will be presented. The surprising difference in the synthesis of hydride complexes by
hydrogenolysis of (C5Me5)2AnMe2, (C5Me4SiMe3)2AnMe2, and (C5Me4H)2AnMe2 will be
described. The utility of (C5Me4SiMe3)1- to generate tethered-ligand complexes will be
discussed. Finally, the first examples of actinide (NC4Me4)1- complexes will be will be
described and compared with (C5Me4H)1- and (NR2)1- analogs.
NUCL 81
Theoretical studies of the structure and bonding in actinide complexes
Bruce E Bursten, [email protected]. Department of Chemistry, University of
Tennessee, Knoxville, TN 37996-1600, United States
the use of modern electronic structure methods, particularly relativistic density functional
theory, has allowed our understandig of structure and bonding in actinide complexes to
grow markedly over the last two decades. The author will present some of the results
from his group that have led to a greater synergy between theory and experiment within
actinide science, particularly in the areas of novel small molecules and actinide
speciation. The author will also thank Dr. Lester Morss for his leadership and vision in
recognizing the importance of such work to help advance this multidisciplinary field.
NUCL 82
On the CmO2 puzzle
Richard L. Martin, [email protected]. Theoretical Division, Los Alamos National
Laboratory, Los Alamos, NM 87506, United States
In this talk I will review the curious case of the electronic ground state of curium dioxide.
Curium in CmO2 should be in the +4 valence, corresponding to an f6 electron count. If
the spin-orbit interaction is presumed to dominate the electronic structure, these six
electrons should completely fill the f5/2 subshell, resulting in a J=0 ground state. On the
other hand, measurements by Morss and colleagues found a sizeable magnetic
moment in CmO2. The origin of this magnetic moment according to hybrid density
functional theory will be presented, and the evolution of the electronic structure in the
actinide dioxides AnO2, An = Th ... Es, discussed.
NUCL 83
Determination of the concentrations and distributions of U and Th in primitive
meteorites by sequential chemical dissolution and ICPMS analysis
Stephen F. Wolf, [email protected], Christopher J. L. Gagnon. Department of
Chemistry and Physics, Indiana State University, Terre Haute, Indiana 47809, United
States
The determination of U and Th in bulk primitive chondritic meteorites has long
presented an analytical challenge to the cosmochemical community. Because these
analyses require the determination of low concentrations (U <10 ng•g-1 and Th <40
ng•g-1) in small samples (<0.1 g), typically in conjunction with complete multielemental
analyses, INAA followed by RNAA was the standard approach. However, over the last
20 years ICPMS has supplanted this approach and made a significant impact in all
aspects of actinide analysis. Here, we utilize ICPMS to measure ultratrace
concentrations (<100 pg•mL-1) of U, Th, and over 60 other major, minor and trace
element constituents in solutions generated from sequential chemical dissolution of
three primitive chondritic meteorites in order gain a greater understanding of the
actinide distribution within the different phases and minerals in these meteorites and
therefore, a greater understanding of the cosmochemical processes that led to their final
disposition.
NUCL 84
Electrochemical and spectroscopic behavior of neptunium in aqueous solutions
Sayandev Chatterjee, [email protected], Amanda J Casella, James M
Peterson, Tatiana G Levitskaia, Samuel A Bryan. Radiochechemical Processing
Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, United States
This work is focused on understanding the aqueous solution chemistry of neptunium
relevent to spent nuclear fuel reprocessing. Neptunium can exist in aqueous solutions in
a range of oxidation states, their stability being dependent on the composition and acid
content of the medium. An in-depth understanding of the relative stability of neptunium
oxidation states in wide range of the acid concentration is critical for the efficient
monitoring of neptunium content and designing of separation processes. Neptunium in
different oxidation states exhibits unique and distinguishable spectral signatures, which
can be effectively used to probe relative stabilities of the respective oxidation strengths
under given conditions. This report will describe both the redox and spectroscopic
behavior of neptunium as a function of the aqueous nitric acid solution concentration.
NUCL 85
Synthesis, reactivity and bonding in uranium(IV-VI) mono- and bis-imido
complexes
James M Boncella1, [email protected], Robert E Jilek1, Enrique R Batista2, Brian L
Scott1. (1) Materials Physics and Applications Division, Los Alamos National
Laboratory, Los Alamos, NM 87545, United States (2) Theory Division, Los Alamos
National Laboratory, Los Alamos, NM 87545, United States
We have discovered convenient synthetic procedures for the preparation of
mononuclear imido complexes of uranium (IV, V and VI). These compounds have
allowed us to explore and compare the reaction chemistry and bonding in uranium
complexes that have the same or very similar ligand sets in three different oxidation
states. The redox chemistry of these compounds will be discussed as will the reactivity
of the imido groups with electrophiles. Changes in the reactivity of the imido groups as a
function of oxidation state correlate with changes in the calculated U-N orbital
interactions that make up the uranium-nitrogen multiple bonds in these compounds. The
relationship between the observed reactivity and the evolving view of covalency in U-L
bonding will be discussed.
NUCL 86
Low temperature route for actinide nitride synthesis from oxide starting materials
Ken Czerwinski, [email protected], Chinthaka Silva, Charles Yeamans, Phil
Weck, Boris Narboux. Chemistry, University of Nevada, Las Vegas, Las Vegas, NV
89154-4003, United States
Synthesis of actinide mononitrides through carbothermic reduction of oxides can result
in the formation of secondary oxide phases as well as low densities of the final product.
A low temperature method for nitride formation has been explored to address issues
related to carbothermic reduction and understand the mechanisms involved in
denitrification toward the final product. The process begins with an ammonium actinide
fluoride species which is then thermally converted to an initial nitride starting material,
often a dinitride. The conversion of the intermediate material to the final nitride product
has been examined for the thorium, uranium, neptunium, and mixed actinide system.
Reaction kinetics, intermediate speciation, and product morphology have been
examined. Methods for preparation of uranium nitride fuels from the dinitride species
are presented. The commonalities and disparities in the system are discussed. The
reactions are evaluated through experimental and computational methods. From the
trends, observations are presented on the utility of the process for the formation of
nitride fuels.
NUCL 87
Thermodynamic and spectroscopic studies of Ln(III)/An(III) complexation with
diethylenetriaminepentaacetic acid
Guoxin Tian, [email protected], Linfeng Rao. CSD, Lawrence Berkeley National
Laboratory, Berkeley, CA 94720, United States
Complexation of DTPA (diethylenetriaminepentaacetic acid) with trivalent lanthanides
and actinides at various temperatures was studied by potentiometry, absorption
spectrophotometry, and fluorescence spectroscopy. Two complex species were
observed, ML2- and MHL-, where M stands for Nd(III)/Eu(III)/Cm(III) and L stands for
diethylenetriaminepentaacetate. The fluorescence data suggest that the DTPA complex
with Cm(III) is deferent from those with Ln(III) structurally and kinetically. In the
complexes of Nd(III)/Eu(III), LnL2- and LnHL-, the Ln(III) is coordinated by an octadentate DTPA/H(DTPA) ligand and a water molecule, while in the DTPA complex with
Cm(III), the hydration number is two or three. The fluorescence data also suggest that
the ligand exchange rate of the Eu(III)-DTPA complexes is higher than that of the
fluorescence decay of Eu(III), while the ligand exchange rate of the Cm(III)-DTPA
complex is lower than that of the fluorescence decay of Cm(III).
NUCL 88
Chemistry of technetium with sulfides
Silvia S. Jurisson1, [email protected], Yongjian Liu1, Eric Weis1, Kim Mason1,
David Rotsch1, Jeff Terry2, Lynn C. Francesconi3. (1) Department of Chemistry,
University of Missouri, Columbia, MO 65211, United States (2) Department of Physics,
Illinois Institute of Technology, Chicago, IL 60616, United States (3) Department of
Chemistry and Biochemistry, Hunter College, New York City, NY 10021, United States
Technetium-99 (Tc-99) is of importance to the nuclear fuel cycle because of its 6%
fission yield, its long half-life (2.12 x 105 years) and its environmental mobility as the
pertechnetate anion. The latter issue has resulted in the contamination of soil, vadose
zone and ground water at nuclear waste storage sites. The chemistry of pertechnetate
with sulfide has been investigated in solution and on solid surfaces as potential mimics
of interactions that might occur in the environment. Speciation studies, immobilization
studies, and stability studies (leaching studies) provide information on potential
reactivity of Tc-99 under various conditions.
NUCL 89
Identification and characterization of a dynamical charge-lattice instability in UO2
Steven D. Conradson, [email protected]. Materials Science and Technology
Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States
XAFS and x-ray and neutron pdfs from UO2, U4O9, and U3O7 find U-O multisite
distributions in the x-ray and simple distributions in the neutron measurements. This
putative contradiction indicates a dynamical character and breakdown of the BornOppenheimer approximation for the “super” polaron in urania. Together with the
apparent homogeneity of the O K edge XAS for these compounds, these results
suggest that the ground state fluorite structure intersects a low lying, uranyl-type of
excited state in a conic intersection. We have also performed ultrafast pump-probe
reflectivity and THz measurements on UO2 that show that the photoinduced
quasiparticles condense into a new phase with the opening of a gap of currently
unknown character at 50–60 K, above the 30 K AFM transition. The quasiparticle
condensate appears to be separate from spin ordering. Summarizing, the interactions of
charge inhomogeneities with the UO2 lattice are exceedingly complicated and point to
new physics.
NUCL 90
Study of the octahaloditechnetate Tc2X8n- (X = Cl, Br; n = 2, 3) anions and their
phosphines derivatives
Frederic Poineau1, [email protected], Paul Forster1, Tanya K Todorova2,
Laura Gagliardi3, Alfred Sattelberger4. (1) Department of Chemistry, University of
Nevada Las Vegas, Las Vegas, NV 89154, United States (2) Laboratory for
Computational Molecular Design, Ecole Polytechnique Fédérale de Lausanne,,
Lausanne, Switzerland CH-1015, Switzerland (3) Department of Chemistry and
Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455, United
States (4) Energy Engineering and Systems Analysis Directorate, Argonne National
Laboratory, Argonne, IL 60439, United States
The technetium dimers (n-Bu4N)2Tc2X8 (X = Cl, Br), [Cs(2+x)][H3O(1-x)]Tc2Br8 (x = 0.22)
and Tc2X4(PMe3)4 (X = Cl , Br), were synthesized and studied by a number of physical
and computational techniques. Single crystal XRD of the acetone solvate of (nBu4N)2[Tc2Br8] revealed a Tc-Tc distance of 2.1625(9) Å) and average Tc-Br distances
of 2.4734[7] Å. The metal–metal separation in Tc2Br83- (2.1261(9) Å) is identical to that
in Tc2Cl83- but is significantly shorter than in Tc2Br82-. The structure and bonding in the
Tc2X8n- (X = Cl, Br; n = 2, 3) systems has been investigated using multiconfigurational
quantum calculations. The structural parameters calculated for the four anions are
within 3% of the experimental values. Effective bond order analysis demonstrates that
the four dimers exhibit similar bond multiplicities and possess an effective triple Tc-Tc
bond. The change of electronic configuration does not affect the total bond order but
does affect the metal-metal bond length. Reactions of (n-Bu4N)2Tc2X8 with
trimethylphosphine were performed in dichloromethane; the new technetium(II) dimers,
Tc2X4(PMe3)4 (X = Cl, Br), were isolated and characterized by single crystal XRD, UVVisible spectroscopy, and cyclic voltammetry. The metal-metal distances are 2.1317(1)
Å for X = Cl and 2.1315(2) Å for X = Br. Calculations predict that the lowest energy
absorption band corresponds to the delta* → sigma* transition.
NUCL 91
Soft X-ray absorption and X-ray emission spectroscopy to elucidate the role of 5f
electrons in actinide materials
David K. Shuh1, [email protected], Roy Copping1, Byoungseon Jeon2,5, Simon J. Teat3,
Markus Janousch4, Tolek Tyliszczak3, Niels Gronbech-Jensen2,5, Andrew Canning5,
Sergei Butorin6, Kristina Kvashnina6, Joseph Nordgren6. (1) Chemical Sciences
Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United
States (2) Department of Applied Science, UC Davis, Daviss, CA 95616, United
States (3) Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley,
CA 94720, United States (4) Laboratory for Synchrotron Radiation, Paul Scherrer
Institute, Villigen, Switzerland (5) Computational Research Division, Lawrence Berkeley
National Laboratory, Berkeley, CA 94720, United States (6) Physics Department,
Uppsala University, Uppsala, Sweden
The participation of 5f-electrons in bonding is a fundamental issue and probing actinide
materials with soft x-rays is a useful approach to elucidate 5f-electron behavior. Uranyl
complexes with the 2,6-Bis(2-benzimidazyl)pyridine (BBP) ligand have been examined
with the scanning transmission x-ray microscope at the light element K-edges and felement N-edges in the soft x-ray region. First-principles electronic structure
calculations of the f-electron bonding reveals hybridization of U atom f-like states with
oxygen and nitrogen states. X-ray emission spectroscopy and resonant inelastic x-ray
scattering (RIXS) also provide information about bonding in 5f-electron materials. Cm
5d RIXS spectra collected from curium oxide show 5f-5f intra-atomic transitions at
energies 1-4 eV below excitation. Differences between RIXS features and calculated
spectra yield evidence for Cm(III). Soft X-ray approaches can impact the understanding
of 5f-bonding in a range of materials and has the potential to aid in the design of
special-purpose actinide materials and ligands.
NUCL 92
Rhenium Schiff base monomers, dimers, and trimers oh my!
David A Rotsch, [email protected], Kimberly M Mason, Anna B Taylor, Eric M
Weis, Silvia S Jurisson. Department of Chemistry, The University of Missouri, Columbia,
Missouri 65211, United States
Metal complexes with Schiff base (SB) ligands have been extensively studied since the
late 1970's for their potential applications in medicine and as commercial catalysts.
Rhenium SB complexes are of particular importance for potential development of
radiopharmaceuticals (Re-186/188) and their chemical similarities to Tc. Reaction of
(Bu4N)[ReOCl4] with SB ligands yields monomeric complexes of the type cis/trans[ReO(SB)X] (X = OH2, Cl-, ReO4-, or RO-) while the identical reaction of ReOCl3(PPh3)2
with SB ligands results in m-oxo dimers of the type trans-[ReO(SB)(μ-O)ReO(SB)].
Spectrochemical data and the conversion of monomers to dimers and back again will be
discussed.
NUCL 93
Preparation of C5 and C6-metallated indole derivatives as precursors for
radiohalogenation
Emily B. Corcoran, [email protected], Anna B. Williams, Robert N.
Hanson. Department of Chemistry and Chemical Biology, Northeastern University,
Boston, Massachusetts 02115, United States
Indoles are the basis of many compounds of biological interest, including the plant
hormone Auxin and tryptamine alkaloids such as serotonin and melatonin. The ability to
radiohalogenate indoles in a way that is compatible with a variety of functional groups
would enable the study of these and other biological systems by PET and SPECT. Due
to the higher specific activities obtained with nucleophilic radiohalogenation as
compared with electrophilic conditions, we used halodemetallations to introduce
radioactive halogens onto the indole scaffold. While the C2 and C3 positions of the
indole have been the typical sites for metallation reactions, palladium-catalyzed
transmetallations at the C5 and C6 positions of the scaffold have been less thoroughly
explored. We will discuss the challenges we have encountered in the synthesis of these
metallated indole derivatives, and the parameters that played a role in the successful
metallation and subsequent radiohalogenations of these compounds.
NUCL 94
Theoretical study of the structure and bonding in actinide carbides
Attila Kovács, [email protected], Peter Pogany, Rudy Konings. Institute for
Transuranium Elements, Eggenstein-Leopoldshafen, Germany
In the last decade, the need for novel fuel types in Generation IV nuclear plant systems
has renewed the interest in actinide carbides. The extreme conditions of the planned
future fast reactors result in a very high temperature in the middle zone of the fuel, and
consequently the carbide vapor appears in the cracks of the fuel. The thermodynamic
description of the vapor requires the knowledge of molecular properties.
We report the electronic and various molecular properties of the actinide (An) carbides
obtained by relativistic quantum chemical calculations. The focus was on the actinide
dicarbides, where there are five possible geometrical arrangements: two triangular
structures including an acetylide moiety, as well as the linear AnCC, CAnC and bent
CAnC geometries. Our calculations at various levels of theory indicate that the
triangular species are energetically more favorable, while the latter three arrangements
proved to be higher-energy structures. We present detailed data on the electronic
structure and bonding properties of the most relevant structures.
NUCL 95
Radical reactions with lanthanide-ligand complexes in aqueous media
Thomas D Cullen, [email protected], Stephen P Mezyk. Department of Chemistry
and Biochemistry, California State University at Long Beach, Long Beach, California
908940, United States
The degradation of organic ligands used in nuclear waste reprocessing is one of the
impediments to the creation of a closed fuel cycle. While considerable research has
recently been performed on the role of the hydroxyl and nitrate radical reactions with a
variety of designer ligands used in the removal of transuranic metal ions from the highly
acidic media used in reprocessing, little is currently known about the damage incurred
by the metal-loaded ligands. We are therefore investigating the impact of these two
main radicals with lanthanide-loaded ligand complexes in acidic aqueous solution. Our
initial ligand of interest is DTPA (diethylenetriamine-pentaacetic acid),used in the
TALSPEAK process. We will report on the kinetics of DTPA loaded with different
lanthanides (Eu, Gd, Ce), and ●OH and ●NO3 radicals as a function of acidity and
temperature obtained utilizing the accelerator facilities at the Radiation Laboratory,
University of Notre Dame.
NUCL 96
Organoactinide hydride complexes of uranium and thorium as multielectron
reductants: Combined neutron diffraction and quantum chemical study
Daniel J Grant1, [email protected], Timothy J Stewart2, Robert Bau2, Kevin
A Miller3, Sax A Mason4, Matthias Gutmann5, Laura Gagliardi1, William J Evans3. (1)
Department of Chemistry, University of Minnesota and Supercomputing Institute,
Minneapolis, MN 55455, United States (2) Department of Chemistry, University of
Southern California, Los Angeles, CA 90089, United States (3) Department of
Chemistry, University of California Irvine, Irvine, CA 92697, United States (4) Institut
Laue-Langevin, Grenoble, France (5) ISIS Facility, Rutherford Appleton Laboratory,
Chilton Didcot, Oxfordshire OX11 0QX, United Kingdom
The unusual uranium reaction in which U4+ and U3+ hydrides interconvert by formal
bimetallic reductive elimination and oxidative addition reactions, [(C5Me5)2UH2]2 ↔
[(C5Me5)2UH]2 + H2, was studied by multiconfigurational quantum chemical and density
functional theory methods. [(C5Me5)2UH2]2 acts a four electron reductant releasing
hydrogen gas as the byproduct of four H- → e- + ½H2 redox couples. The calculated
structures are in good agreement with X-ray diffraction data on [(C5Me5)2UH]2 and
[(C5Me5)2UH2]2, and neutron diffraction data on [(C5Me5)2UH2]2 obtained under
hydrogen pressure. The interconversion reaction of the U4+ and U3+ hydrides was
calculated to be near thermoneutral (-2 kcal/mol) while that of the unknown thorium
analog, [(C5Me5)2ThH]2, was predicted to be largely endothermic (26 kcal/mol). The
analogous reactions for the tetramethylcyclopentadienyl hydride systems,
[(C5Me4H)2AnH2]2 → [(C5Me4H)2AnH]2 + H2 (An = Th, U) were also studied allowing for
an energetic and structural comparison to the previous pentamethylcyclopentadienyl
systems.
NUCL 97
On the boron-loaded liquid and polymeric scintillators for the detection of thermal
neutrons
Zheng Chang, [email protected]. Department of CMET & Nuclear Engineering, South
Carolina State University, Orangeburg, South Carolina 29117, United States
The boron-loaded liquid and polymeric scintillators were studied systematically in order
to understand the effect of the components on the scinitllation efficiecy for the detection
of thermal neutrons. The key components of the scintillators were recognized as
primary and secondary scintillent, primary and secondary flours, and 10B-carrier
species. Carborane was found as an excellent Boron carrier for neutron capture. The
scinillation effciency was evaluated by the absolute light yield, photopeak area, peak
energy, and pulse height deficit.
As to liquid organic scintillators, it was found that the samples with toluene and 1,2,4trimethyle bezene as the primary scintillent and naphthalene as the secondary scintillent
show the highest scintillation efficiency. For polmeric scintillators, it was found that the
polymer matrix plays key role to the scintillation efficiency. The polymethyl toluene
matrix is generally transparent and shows the best scintillation efficiency.
NUCL 98
High linear energy transfer (LET) induced radiolysis of the extraction ligand
tributyl phosphate via the 10B(n,α)7Li reaction
Jeremy Pearson1, [email protected], Oliver Jan1, George Miller2, Mikael Nilsson1. (1)
Department of Chemical Engineering, University of California Irvine, Irvine, CA 92697,
United States (2) Department of Chemistry, University of California Irvine, Irvine, CA
92697, United States
Solvent extraction reprocessing of used nuclear fuel is hindered by radiation induced
damage to extraction ligands. The extent of degradation may vary depending on the
type of radiation. Initial degradation studies using gamma radiation have been
performed on tributyl phosphate (TBP) but very few have been performed using alpha
particles or other particles with similar high linear energy transfer (LET) characteristics.
Here we investigate the utility of using the 10B(n,α)7Li reaction for studying high LET
radiolysis of extraction ligands. Alpha-like particles He2+ (1.5 MeV) and Li+ (0.85 MeV)
are created in situ with similar energy and LET value to alpha particles of ~5 MeV
emitted from used nuclear fuel. TBP degradation is quantified by gas chromatography
and mass spectrometry. Both gamma and high LET g-values for TBP disappearance
are reported as well as g-values for common degradation products such as dibutyl
phosphoric acid, monobutyl phosphoric acid, and phosphoric acid.
NUCL 99
Modes of metal ion transfer into ionic liquids (ILs): Implications for the
application of ILs as extraction solvents
Sarah L Garvey, [email protected], Cory A Hawkins, Anna Rud, Mark L Dietz.
Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee,
Milwaukee, WI 53211, United States
The rational design of ionic liquid-based metal ion separation systems requires either
that the ion transfer properties of these systems be predictable from the known behavior
of conventional organic solvents or that the mechanism(s) of ion transfer be understood
at a fundamental level. With this in mind, we have examined the extraction of selected
metal ions (e.g., alkaline earths and pertechnetate) from aqueous media into a series of
N,N'-dialkylimidazolium-based room-temperature ionic liquids (RTILs) , either alone or in
the presence of crown ethers. The results obtained indicate that although certain
aspects of metal ion extraction into RTILs parallel the behavior of conventional solvents,
ionic liquids frequently play a much more active role in the partitioning process, with ion
exchange involving the cationic or anionic constituents of the ionic liquid comprising an
important mode of ion transfer.
NUCL 100
Investigation of metal ion extraction and aggregate formation combining acidic
and neutral organophosphorous reagents
Alexander Braatz1, [email protected], Timothy Anderson1, Ross Ellis2, Mark Antonio2,
Mikael Nilsson1. (1) Chemical Engineering, University of California, Irvine, Irvine,
California 92617, United States (2) Argonne National Laboratory, Argonne, Illinois
60439, United States
In solvent extraction systems for the purification of spent nuclear material aggregation
phenomena can interfere with the efficiencies of the processes. The predictability of
these phenomena have been challenging due to the lack of a fundamental
understanding of the mechanism that drives these aggregate formations. To investigate
the aggregation more closely, tri-n-butyl phosphate (TBP) and dibutyl phosphate (DBP)
in n-dodecane were chosen as the organic phase to be contacted with an aqueous
phase containing a single metal ion from the lanthanide series. The extraction of
lanthanum and dysprosium from nitrate solutions at various metal ion concentrations
was investigated. Third phase was observed in dysprosium samples of high metal ion
concentration. Extraction isotherms and limits of the concentration where phase splitting
occurs will be presented in an attempt to describe the nature of the third phase.
Separate studies of the X-ray scattering behavior of these solutions will also be
presented.
NUCL 101
Vapor pressure osmometry determination of select organic phase activity
coefficients applicable to spent nuclear fuel reprocessing
Michael F Gray1, [email protected], Mikael Nilsson1, Peter Zalupski2. (1) Department of
Chemical Engineering, University of California, Irvine, Irvine, CA 92697, United
States (2) Aqueous Separations and Radiochemistry Department, Idaho National
Laboratory, Idaho Falls, Idaho 83415, United States
The technique of vapor pressure osmometry is utilized to revisit organic phase activity
coefficients to help ensure accurate treatment of the non-ideal affects in modeling of
separations for nuclear fuel reprocessing, and to further elucidate the impact of the
solvent. Here, we present and analyzes our osmometry results for di(2-ethylhexyl)
phosphoric acid, (HDEHP), an industrial extractant that can be used in the separation of
lanthanides from actinides. This study examines several solvents, including the
commonly studied dodecane and toluene, allowing comparison with with prior studies
that used the alternative technique of slope analysis of metal extractions to correct for
non-ideal interactions of HDEHP in the organic solvent. Our work will help reveal effects
overlooked by those extractions studies or independently confirm their results.
NUCL 102
Towards ab inito modeling of actinide chemistry and redox in realistic
environments
Wibe A de Jong1, [email protected], Eric J Bylaska1, Raymond Atta-Fynn1,
Donald F Johnson1, Ping Yang1, Vassiliki A Glezakou2. (1) EMSL, Pacific Northwest
National Laboratory, Richland, WA 99352, United States (2) Chemical Physics and
Analysis, Pacific Northwest National Laboratory, Richland, WA 99352, United States
Understanding the dynamical behavior of actinide species interacting with their
environment is important to further the development effective remediation strategies and
ensure safe nuclear processes. Computational chemistry has reached the point where it
makes significant contributions to the fundamental understanding of actinide chemistry,
and plays an important role in interpretation of experimental data and the prediction of
chemical and physical behavior of actinide species in the subsurface.
With highly scalable heavy-element chemistry software capabilities in NWChem we are
exploring the dynamical behavior of actinide species in aqueous environments and at
mineral interfaces, employing ab initio molecular dynamics techniques. We will present
recent advances and results of simulations targeted to model the thermochemistry of
uranium and other actinide species, such as curium, in realistic environments including
ions in solution and complex solution-mineral interfaces. Mineral surfaces we are
studying include alumina, iron oxides, and iron sulfides.
NUCL 103
Combined computational and electrochemical approach to determine the redox
reaction mechanism of actinide oxides on sulfide surfaces
Udo Becker, [email protected], Devon Renock, Rodney C Ewing. Department of
Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United
States
Little is known about the reaction mechanism of actinyl complexes on mineral surfaces,
i.e. the role of the redox potential, the nature of the reductant, the importance of
minerals in terms of providing catalytic surfaces, the role of anions in solution that
polarize a mineral surface to promote or inhibit electron transfer, and the activated
states that may slow down the kinetics of the redox process. In order to resolve these,
an electrochemical studies using a micropowder electrode technique were performed in
combination with a quantum-mechanical approach. The electrochemical approach
allows us to determine the specific redox potential of actinide reduction on a given
mineral surface. For example, uranyl reduction takes place at -0.22 V on hematite, -0.17
V on magnetite, and at -0.14 V on pyrite. The calculations show that the energy gain of
the co-adsorption of hydroquinone (as an analogue for microbial reduction) and uranyl
is on the order of 0.5 eV (»50 kJ/mol) as compared to the separate adsorption of uranyl
and hydroquione. Similar co-adsorption on FeS (mackinawite) reveals that Fe(II) cations
in the mineral surface become high spin (Fe(II) in bulk mackinawite is low spin), thereby
increasing its potential for electron transfer.
NUCL 104
Technetium alloy waste form development for advanced fuel cycles
Gordon D Jarvinen1, [email protected], David Kolman1, Kristy M Long1, George S
Goff1, Michael Cisneros1, Rowena Gibson1, Kenneth R Czerwinski2, Frederic Poineau2,
Edward Mausolf2. (1) Los Alamos National Laboratory, Los Alamos, NM 87545, United
States (2) Department of Chemistry, University of Nevada, Las Vegas, Las Vega, NV
89154, United States
In advanced recycle schemes for used nuclear fuels, technetium is a fission product of
particular concern because of its high fission yield, long half-life, and high solubility and
mobility in groundwater as pertechnetate. As part of the Fuel Cycle Technologies
Program of the DOE Office of Nuclear Energy, we have been preparing and
characterizing metal alloys containing Tc and other fission product metals as potential
waste forms. The initial suite of alloys under study include iron or stainless steel as a
major component to build on the previous work on alloy waste forms done for the
electrochemical processing of used fuel from the Experimental Breeder Reactor-II. The
phases in these alloys and their dissolution behavior under a range of aqueous
conditions are being characterized by a variety of methods including scanning electron
microscopy, elemental mapping, linear polarization resistance, and electrochemical
impedance spectroscopy. Recent results will be reviewed.
NUCL 105
Templated uranium diphosphonates: Synthesis and structure characterization
Anna-Gay D Nelson1,2, [email protected], Rodney C Ewing1, Thomas E AlbrechtSchmitt2. (1) Department of Earth and Environmental Sciences, University of Michigan,
Ann Arbor, Michigan 48109-1005, United States (2) Department of Civil Engineering
and Geological Sciences and Department of Chemistry and Biochemistry, University of
Notre Dame, Notre Dame, Indiana 46556, United States
The hydrothermal treatment of uranium trioxide and methylenediphosphonic acid with a
variety of amines (4, 4 dipyridyl, 2, 2 dipyridyl, triethylenediamine, ethylenediamine, and
1-10 phenanthroline) at 200 ºC results in the crystallization of a series of layered
uranium diphosphonate compounds, [C10H10N2]{UO2[CH2(PO3H)2]} (Udip1 ),
[C10H10N2]{UO2[CH2(PO3H)2]·(H2O)} (Udip2 ),
[C6H14N2]{(UO2)2[CH2(PO3)(PO3H)]·n(H2O)} (UDAB ),
[C2H10N2]{(UO2)2(H2O)2[CH2(PO3H)2]2·(H2O)} (Uethyl1 ),
[C2H10N2]{U[CH2(PO3H)2]2·H2O} (Uethyl2 ), and [C12H10N2]{UO2(H2O)[CH2(PO3H)2]
(Uphen ). All these compounds contain the UO22+ moiety bound by bridging and
chelating diphosphonic ligands, creating coordination environments ranging from UO6
tetragonal bipyramids, UO7 pentagonal bipyramids and UO8 distorted dodecahedrons.
The incorporation of the amine templates serves both as structure directing agents and
charge balancing cations for the anionic uranium phosphonate sheets, in the formation
of the different coordination geometries and topologies attained in each structure.
NUCL 106
Fundamental studies of AnO2+ cation-cation complexes in aqueous and nonaqueous media
John W Freiderich1, [email protected], Leigh R Martin2, Kenneth L Nash1. (1)
Department of Chemistry, Washington State University, Pullman, Washington 991644630, United States (2) Idaho National Laboratory, Idaho Falls, ID 83415-6150, United
States
Cation-cation complexes of oxidized actinide ions were first reported fifty years ago by
Sullivan and coworkers. Though the first noted complex was between NpO 2+ and UO22+,
similar species have been reported involving NpO2+, UO2+ and AmO2+ and a variety of
high valent transition metal, main group and actinide species. In these complexes
AnO2+ behaves as a ligand, probably bonding via the "yl" oxygen to form a coordination
complex with AnO22+ or other high charge density cations. From a practical applications
perspective, cation-cation complexes may have significance when processing used
nuclear fuel on an industrial scale, particularly species involving NpO2+. In this report,
spectrophotometric and electrochemical methods have been used to deduce
information about the thermodynamics of the reactions AnO2+ + AnO22+ ↔
[AnO2·AnO2]3+ and AnO2+ + M3+ ↔ [AnO2·M]4+. The influences of water activity, nonaqueous solvents, complexing versus non-complexing anions, and temperature on the
stability of these complexes are discussed.
NUCL 107
Actinide chemistry from a gas-phase perspective
John K Gibson1, [email protected], Joaquim Marçalo2, Maria C Michelini3, Daniel
Rios1, Ana F Lucena2, Philip X Rutkowski1. (1) Chemical Sciences Division, Lawrence
Berkeley National Laboratory, Berkeley, CA 94720, United States (2) Unidade de
Ciências Químicas e Radiofarmacêuticas, Instituto Tecnológico e Nuclear, Sacavém,
Portugal (3) Dipartimento di Chimica, Università della Calabria, Arcavacata di Rende,
Cosenza, Italy
Our ongoing studies of actinide chemistry in the gas phase offer insights into behavior
at a fundamental level, free of perturbations introduced in condensed phases. The
studied systems are often adequately simple that reliable characterization can be
provided by density functional theory. Recent representative experiment and theory
results will be presented for elementary reactions of bare and ligated actinide ions with
neutral hydrocarbons and other small molecules. A new experimental thrust, the
preparation and chemistry of gas-phase actinyl complexes, is providing insights into
gas-phase coordination chemistry as well as opportunities for synthesis of new types of
actinide moieties via ligand activation and decomposition.
This work is supported by the U.S. Department of Energy, Office of Basic Energy
Sciences; by Fundação para a Ciência e a Tecnologia, Portugal; and by Università degli
Studi della Calabria, Italy.
NUCL 108
Exploring actinide chemistry with multiconfigurational quantum chemical
methods
Laura Gagliardi, [email protected]. Department of Chemistry, University of
Minnesota, Minneapolis, MN 55455, United States
Quantum chemistry can be applied to the study of systems containing any atom in the
periodic table. I will start the lecture with an introduction about quantum chemistry and
actinide-containing systems. I will then describe our recent studies of uranyl peroxide
nanoclusters, with the aim of understanding the basic principles responsible for selfassembly of such systems.[1] I will also report the results of our study of the reaction
[(C5Me5)2UH2]2 [(C5Me5)2UH]2 + H2, which corresponds to the interconversion of the U4+
and U3+ hydride species.[2]
[1]P. Miro, B. Vlaisavljevich, C.J. Cramer, L. Gagliardi, P. C. Burns Growth Mechanisms
of Uranyl-Peroxide Nanoclusters Submitted
[2] D. Grant, T. J. Stewart, R. Bau, K. A. Miller, S. A. Mason, M. Gutmann, L. Gagliardi,
W J. Evans Organoactinide Hydride Complexes of Uranium and Thorium as
Multielectron Reductants: A Combined Neutron Diffraction and Quantum Chemical
Study Submitted
NUCL 109
Separation of americium from trivalent lanthanides using pyridine-based
receptors
Lætitia H. Delmau1, [email protected], Rachel Severance2, Peter Bonnesen1. (1)
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831,
United States (2) University of South Carolina, Columbia, SC, United States
Spent nuclear fuel consists of four primary categories of waste: short-lived isotopes,
short-lived fission products, long-lived actinides, and long-lived fission products. Of
these, the long-lived actinides are particularly difficult to separate from the shorter-lived
lanthanide fission products. Yet, the isolation of the minor actinides from the lanthanides
significantly reduces the volume of long-lived nuclear waste, and also allows
transmutation of the actinides to isotopes with shorter half-lives. Alternatives to the
TALSPEAK process for the selective separation of minor actinides, particularly
americium and curium, from lanthanides in actual spent fuel are being investigated.
One class of compounds with selectivity for americium and curium under the necessary
conditions is pyridine-based receptors. These nitrogen-based BTP/BTBP/BTPhen
ligands are desirable for both separation ability and for being incinerable, and can
remove pH control and aqueous complexants from the extraction process requirements.
The presentation will highlight several ligands in this class which were analyzed for their
respective stability, solvability in Cs-7SB/Isopar L, and separation ability when in contact
with both nitric and hydrochloric acid. In particular, a relatively stable ligand in this class
was synthesized in house, characterized via NMR, and studied for extraction ability in
this solvent/modifier system.
NUCL 110
Binary technetium chlorides
Alfred P. Sattelberger1, [email protected], Frederic Poineau2, Erik V. Johnstone2,
Phillipe F. Weck2, Eunja Kim2, Paul Forster2, Kenneth R. Czerwinski2. (1) Energy
Engineering and Systems Analysis Directorate, Argonne National Lab, Lemont, IL
60439, United States (2) Department of Chemistry, University of Nevada Las Vegas,
Las Vegas, NV 89154, United States
One of the more fundamental aspects of transition metal chemistry is the reaction of the
individual metals with the elemental halogens to form binary halides. The latter are
useful starting materials for a host of important applications. In the case of technetium,
only three binary halides, viz., TcF6, TcF5 and TcCl4, were known prior to 2009. The
reaction between technetium metal and elemental chlorine at elevated temperatures in
sealed Pyrex tubes provides three isolable products – TcCl2, beta-TcCl3, and the
previously reported TcCl4 – depending on the stoichiometry and reaction conditions. In
this talk, we will describe the syntheses, physical and theoretical characterization, and
solid-state structures, as well as the conversion of beta-TcCl3 to alpha-TcCl3 (Tc3Cl9).
NUCL 111
Tetravalent actinide nanoparticles in aqueous solution: Structure and reactivity
L. Soderholm1, [email protected], Karah E. Knope1, S. Skanthakumar1, Richard E. Wilson1,
Yung-Jin Hu1, Monica Vasiliu2, David A. Dixon1,2. (1) Chemical Sciences and
Engineering, Argonne National Laboratory, Argonne, IL 60439, United States (2)
Department of Chemistry, The University of Alabama, Tuscaloosa, AL 35487, United
States
Hydrolysis and subsequent condensation reactions play an important role in the
aqueous chemistry of tetravalent actinide ions. The resultant oligomers are known to
exhibit a chemistry very different from that of their monomeric counterparts. Long
thought to be intractable, amorphous, and chemically ill-defined, our recent structural
and property characterization, both in solution and in the solid state, is revealing a very
different picture. The hydrolysis products are often well defined nanoparticles that can
be crystallized and structurally characterized via standard single-crystal techniques. The
presence of these oligomeric species in solution, often as monodisperse nanoclusters,
is verified by high-energy x-ray scattering (HEXS). Included in this presentation will be
the impact of our results on understanding the role of colloids in both geochemical
modeling and nuclear-waste reprocessing. This work was performed for the U.S. DOE,
OBES, Division of Chemical Sciences, Geosciences, and Biosciences, under contract
DE-AC02-06CH11357.
NUCL 112
U and Zr speciation in soils collected at the Chernobyl Nuclear Power Reactor
accident
Steven D. Conradson, Olga N. Batuk, [email protected]. MST-8, Los Alamos National
Laboratory, Los Alamos, NM 87544, United States
We studied structural variability from U oxide, Zr oxide and U-Zr mixed oxide samples
using synchrotron-based microprobe spectroscopy. We initiated this work through
measurements and analyses of soil samples collected in July 1986 at 1.5 km west-westnorth of the Chernobyl Nuclear Power Reactor accident. Chemical measurements were
carried out at the Stanford Synchrotron Radiation Laboratory BL 2.3. Elemental imaging
of the samples to identify particles of interest, determination of U and Zr oxidation state
was measured with micro Extended X-ray Absorption On the scale of tens to hundreds
of µm, comparable to many of the individual homogeneous particles, inhomogeneous
particles are divided into smaller, relatively homogeneous domains. These results
indicate a mechanism where the fire would have originally caused thorough, atomic
scale mixing of materials in proximity at the time of their combustion or thermal
decomposition, followed by a period where particles from many sources were mixed
and could agglomerate.
NUCL 113
Investigation of the radioiodine binding environment in terrestrial aquatic natural
organic matter by FT-ICR-MS
Chen Xu1, [email protected], Yuko Sugiyama2, Patrick G Hatcher3, Saijin
Zhang1, Hsiu-Ping Li1, Yi-Fang Ho1, Kathleen A Schwehr1, Daniel I Kaplan4, Kimberly A
Roberts4, Robin Brinkmeyer1, Chris Yeager4, Peter H Santschi1. (1) Department of
Oceanography and Marine Science, Texas A&M University at Galveston, Galveston, TX
- Texas 77553, United States (2) University of Hyogo, Okayama, Japan (3) College of
Sciences, Old Dominion University, Norfolk, VA 23529, United States (4) Savannah
River National Laboratory, Aiken, SC 29808, United States
129
I has been recognized by the U.S. Department of Energy as a high risk radionuclide
in groundwater at some DOE sites. Transport of released 129I from a nuclear waste
depository can occur via groundwater, wet or dry deposition, and/or surface runoff.
Compelling evidence indicates that the presence of natural organic matter (NOM) exerts
a primary control on iodine retardation in terrestrial aquatic systems (Xu et al., 2011a,
b).
This molecular level study presents new results from the application of electrospray
ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass
spectrometry (FT-ICR-MS) that investigates the binding properties of radioiodine by
NOM. From our results we can identify a) binding sites of radioiodine; b) relative
reactivity of NOM fractions towards iodine; c) iodinated compounds produced through
enzymatic or abiotic pathways.
References:
Xu C. et al. (2011) GCA, 75, 5716-5735.
Xu C. et al. (2011). ES&T, In revision.
NUCL 114
Uranyl adsorption and speciation at the mineral/water interface studied by
second harmonic generation
Sarah A Saslow1, [email protected], Jessica N Malin2, David S
Jordan1, Franz M Geiger1. (1) Department of Chemistry, Northwestern University,
Evanston, IL 60208, United States (2) Department of Crop Protection, DuPont, Newark,
DE, United States
Uranyl adsorption to the silica surface was studied by second harmonic generation
(SHG). Resonantly enhanced SHG was used to measure an in situ electronic spectrum
of adsorbed uranyl species at both pH 7 and pH 4, and in the presence of aqueous
carbonate. By monitoring the SHG response, adsorption isotherms revealed that the
adsorption free energy for U(VI) at the silica/water interface increased from –42.7(3)
kJmol-1 at pH 7 to –32.5(3) kJmol-1 at pH 4. By using the non-resonant χ(3)technique,
surface charge densities of adsorbed uranyl species were determined to be 0.0069(7)
Cm-2 at pH 7 and 0.0031(5) Cm-2 at pH 4. When these values are referenced to the
initial charge density of the interface, results indicate a bidentate mode of binding at pH
7 and a mondentate mode of binding at pH 4. Free energy vs. interfacial potential
analysis revealed that neutral and monovalent cationic uranyl species are surface active
in both aqueous pHs. Using these same methodologies, this work is now applied
separately to the muscovite (mica) and Fe2O3/water interface, which is discussed.
NUCL 115
Formation and stability of oxidation-state-specific actinide colloids in high ionicstrength brine
Donald T Reed, [email protected] and Environmental Sciences, Los alamos
National Laboratory, Carlsbad, NM 88220, United States
The Waste Isolation Pilot Plant (WIPP) transuranic repository remains a cornerstone of
the U.S. Department of Energy's (DOE) nuclear waste management effort. The
contribution of colloidal species to the overal dissolved actinide concentration is a key
and critical input to the low-probability potential for release from the TRU repository. The
colloidal fraction of actinides and analogs is established by a combination of sequential
filtration (down to ~ 7 nm) and by ultracentrifugation (up to 130,000 rpm, Beckman
ultracentrifuge). The results obtained in our long-term thorium solubility studies indicate
relatively small colloidal effect (a factor of 2 or less) which is considerably less than
reported in the literature for shorter-term experiments. Similarly small effects were
observed for long-term plutonium and neodymium solubility studies. These data,
together, show a relatively small but significant tendency to form intrinsic colloids in the
high ionic-strength brines investigated.
NUCL 116
Speciation of U and Pu in soils from Chernobyl, Hanford, Los Alamos, McGuire,
Mayak, and Rocky Flats
Steven D. Conradson, [email protected], Olga N. Batuk. Materials Science and
Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United
States
A principal assumption at the basis of environmental chemistry is that contaminants
transform quickly to the thermodynamic minima for their local conditions. For actinides
in soils exposed to air and water these are typically oxy-hydroxide species that may be
homogeneous or surface complexes and precipitates. However, bulk and microfocused
XAFS and element-mapping measurements on U and Pu-containing particles from the
six sites listed in the title show that, in many cases, this path is not followed.
Contaminant particles are often found to have incorporated additional elements from
their formation, original waste streams, or disposal processes that reflect their origin and
history. This includes components of the original devices, e.g., fuel elements or
thermonuclear weapons, reagents used in separations, and perhaps even the storage
tanks or pipes. These traces are conserved even after decades of environmental
exposure. Furthermore, the their incorporation may occur in the solid state and not
require dissolution.
NUCL 117
Plutonium and neptunium sorption to goethite: Affinity, morphology, and kinetics
as a function of surface load
Mavrik Zavarin1, [email protected], Pihong Zhao1, Ruth Maria Tinnacher2, Brian A.
Powell3, Zurong Dai1, Mathew Snow4, Annie B. Kersting1. (1) Physical and Life
Sciences Directorate, Glenn T. Seaborg Institute, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States (2) Earth Sciences Division,
Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States (3)
Department of Environmental Engineering and Earth Sciences, Clemson University,
Clemson, South Carolina 29625, United States (4) Department of Chemistry,
Washington State University, Pullman, Washington 99164, United States
In the environment, Pu migration has been observed to occur with the colloidal fluid
fraction, and often associated with minerals colloids. However, the nature of the
actinide-mineral association and its stability will govern the effectiveness of this colloidfacilited transport process over time and space. We summarize a number of
experiments performed on goethite to elucidate the form, stability, and reversibility of
sorption reactions and discuss whether these sorption phenomena can lead to
kilometer-scale colloid-facilitated Pu transport, as has been reported from field sampling
at the Nevada National Security Site (formerly Nevada Test Site) and elsewhere.
Experimental data to be presented include Pu(IV), Pu(V) and Np(V) batch sorption
experiments performed over a ten order of magnitude actinide concentration range (10 6
~10-16 M) that examine sorption linearity, flow-cell experiments that examine sorption
hysteresis and kinetics, and TEM/nano-SIMS data which examine the morphology of
sorbed Pu and Np.
Prepared by LLNL under Contract DE-AC52-07NA27344.
NUCL 118
Nature of nanosized plutonium particles in the Hanford 216-Z9 Crib sediments
Edgar C Buck1, [email protected], Andrew R Felmy1, Dean A Moore1, Kenneth R
Czerwinski2. (1) Pacific Northwest National Laboratory, Richland, WA 99352, United
States (2) Department of Chemistry, University of Nevada, Las Vegas, Las Vegas,
Nevada 89154, United States
The occurrence of plutonium oxide either from direct deposition or from the precipitation
of plutonium-beairng solutions in contaminated soils and sediments has been well
described, particularly for the Hanford site in Washington State. However, the large size
of these particles suggests that they play little role in the long term migration of
plutonium. We present evidence for the formation of plutonium-phosphate nanoparticles
in 216-Z9 crib sediments from Hanford using transmission electron microscopy (TEM).
Fine electron probes were used to obtain electron diffraction patterns and electron
energy loss spectra from specific phase regions of the 216-Z9 crib specimens from fine
grained plutonium silico-phosphate phases (see
). These unique nano-sized plutonium phosphates in the sediments may control the
long term migration of Pu in the soil.
NUCL 119
Investigating the transport of plutonium in vadose zone sediments at the Hanford
Site using NANOSIMS
Ruth Kips1, [email protected], Peter K. Weber1, Mavrik Zavarin1, Andrew R. Felmy2,
Annie B. Kersting1. (1) Glenn T. Seaborg Institute - Physical and Life Sciences
Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550,
United States (2) Pacific Northwest National Laboratory, Richland, Washington 99352,
United States
During the history of the Hanford Site, plutonium production for the U.S. nuclear weapon
program resulted in discharges of transuranic liquid waste to the vadose zone. Soil
samples collected from 15 to 20 m vertical depth below ground surface were examined
using high spatial resolution secondary ion mass spectrometry (NanoSIMS). NanoSIMS
analysis provides elemental as well as isotopic ratio information at the nano-scale.
These measurements detected plutonium co-located with silicate minerals.
Complementary analyses using energy dispersive X-ray analysis and X-ray diffraction
were used to determine the mineral phases.
Prepared by LLNL under Contract DE-AC52-07NA27344.
NUCL 120
Stability of plutonium colloids in the presence of montmorillonite clay at elevated
temperatures-a novel approach
Pihong Zhao, [email protected], Mavrik Zavarin, Zurong Dai, Susan A Carroll, Annie B
Kersting.Glenn T. Seaborg Institute, PLS, Lawrence Livermore National Laboratory,
Livermore, CA 94550, United States
Colloid-facilitated plutonium transport is often found to be the dominant mechanism
controlling its migration in the environment. However, the form of Pu (intrinsic versus
pseudo-colloid) and its stability is not well understood. Accurate prediction of colloidfacilitated transport requires an understanding of the underlying mechanisms and rates
that control the stability of colloidal plutonium. In this study, we examine the stability of
intrinsic Pu colloids relative to Pu-montmorillonite pseudocolloids.
Dialysis membranes were used to segregate Pu intrinsic nano-colloids (2-5 nm) from
montmorillonite colloids (>100 nm) and allow Pu aquo (<1 nm) species to establish
equilibrium between both colloidal phases. Experiments were conducted at both room
temperature and 80°C under atmospheric conditions. Using the dialysis membrane
approach, we determined that Pu intrinsic nano-colloid formation is reversible, though
dissolution is kinetically limited. The data suggest that Pu intrinsic nano-colloids will tend
to dissolve in the presence of montmorillonite and yield Pu pseudocolloids. The
reversible nature of intrinsic colloid formation suggests that their migration may be
limited. Prepared by LLNL under Contract DE-AC52-07NA27344.