Download PREM NMHU Highlights - FY 14-15

n-Type Metallocene Dopants for Organic Thin-Film
Transistors and Other Applications
Evgheni Jucov, Siyuan Zhang, Benjamin D. Naab, Zhenan Bao,
Marina Fonari, Stephen Barlow, Seth R. Marder, Tatiana V.
Timofeeva
NMHU, DMR 0934212
The promise of low-cost processing and flexible circuitry has driven intense research in carbon-based
electronics. The performance of carbon-based materials can be effectively tuned by the application of redox reagents
dopants, through increasing the conductivity and decreasing the injection barrier. Two ferrocene and two ruthenocene
substituted compounds (1-4) were investigated with X-ray single crystal analysis. These compounds represent a
series of new benzimidazole-based n-type dopants, which can be used to dope a variety of semiconductors for
organic thin-film transistors (OTFTs) and other applications. They react (faster than similar air-stable organic dopants)
with a variety of electron-transport materials, including fullerenes and perylene diimides, to form the corresponding
radical anions and monomeric benzimidazolium cations. Studied compounds are proved to be effective dopants for a
variety of vapor- and solution-processed materials.
Crystal data and structure refinement
1
3
2
Structures of 1-4
4
Studies of the MOFs and Charge Transfer Materials
Carlos Ordonez, Raul Castaneda, Dr. Marina Fonari, Dr. Qiang
Wei, Dr. Tatiana Timofeeva
NMHU, DMR 0934212
At NMHU under supervision of Prof. Wei (Ordonez, Fonari) a series of anionic MOFs {Zn-BTC}{Cations} with tunable
fluorescence controlled by the counter cations was synthesized and studied. All MOFs with anionic frameworks are
constructed from Zn2+ with 1,3,5-benzenetricarboxylate (BTC) organic anions. Cations include NH4+, MeNH3+, Me2NH2+,
Et2NH2+, n-Bu2NH2+, n-Bu4N+, BzMe3N+, Me4N+, and 1-Butyl-3-methylimidazolium (BMIM). The influence of various
counter cations on the structural changes of the anionic Zn-BTC connections in the frameworks, and on the
fluorescence of the corresponding MOFs was examined. It was observed that cations are acting as structure-directing
agents affecting the type of coordination in the anionic frameworks.
{Zn-BTC}{Cations} MOFs structure changes from 1D chain to 2D
layer, and to 3D frameworks
Dependence of fluorescence
characteristics of MOFs
dimensionality.
Series of potential charge-transfer materials
containing donor and acceptor molecules in
one crystal was synthesized and studied using
X-ray diffraction analysis. Stacks of molecules
found in crystals support their charge-transfer
properties.
Ratio of components and crystal
shape for Hg3-TTF adducts.
Molecular packing in adducts
presented in figure to the left
Hg3- red, TTF-yellow, solventgreen.
Presentations for Las Vegas High School Students
(MESA Event)
April 7, 2014, NMHU, Las Vegas, NM
Evgheni Jucov, Erika Guaba, Carlos Ordonez, Raul Castaneda,
Marie Ohoueu
NMHU, DMR 0934212
Laboratory tour and presentations
on materials science and solar cells
development was carried out at New
Mexico Highlands University for
students from Las Vegas high
schools. The presentation explained
to local students why solar energy is
an important source of renewable
energy in New Mexico and how
materials studies can impact solar
cells development.
Students at organic
chemistry lab
Students at crystallography lab
Group picture
Demonstration of unmanned
aircraft at physics lab
PREM GRADUATES 2009-2015
Electron-Transport Materials - Merocyanines
Challenge - intermolecular dye-dye interactions lead to aggregation that
adversely affects the third-order nonlinear optical properties in
high-chromophore density films
Strategy - the oxidative addition of halogen-functionalized dyes to Pt(PPh3)4
to modify the molecular shape (Marder group, GA Tech)
Result
- bulky Pt(PPh3)2Hal groups in the “bay” positions of perylene
diimides (PDIs) prevent aggregation, and thus the PDIs were found
to show favorable molecular-level properties
Chemical and crystal structure of a perylene
diimide (PDI) with bulky organoplatinum
substituents (Timofeeva group, NMHU)