Inorganic Chemistry 412 / 512
... (a) Use Wade’s rules to determine the number of cluster-bonding electron pairs and the structure type (closo, nido, or arachno) in B4H10 . [7 pts] 4 B-H + 6 H = 4 (2) + 6 = 14 cluster bonding electrons, or 7 electron pairs. The number of vertices, n, is the number of B atoms (4), sp this is an (n+3) ...
... (a) Use Wade’s rules to determine the number of cluster-bonding electron pairs and the structure type (closo, nido, or arachno) in B4H10 . [7 pts] 4 B-H + 6 H = 4 (2) + 6 = 14 cluster bonding electrons, or 7 electron pairs. The number of vertices, n, is the number of B atoms (4), sp this is an (n+3) ...
A Lead-Filled G-Quadruplex: Insight into the G
... In addition to providing general insight into G-quartetcation interactions, studying Pb2+ binding to nucleobases may result in a better understanding of the molecular basis for lead’s genotoxicity.22 While lead’s coordination chemistry is well understood,23 there are few structural details regarding ...
... In addition to providing general insight into G-quartetcation interactions, studying Pb2+ binding to nucleobases may result in a better understanding of the molecular basis for lead’s genotoxicity.22 While lead’s coordination chemistry is well understood,23 there are few structural details regarding ...
Classes of organic acids and bases
... Neutral organic bases contain one or more pairs of nonbonding electrons. • When acting as Lewis bases these e- pairs are donated. ...
... Neutral organic bases contain one or more pairs of nonbonding electrons. • When acting as Lewis bases these e- pairs are donated. ...
Defects in ceramic structure 2
... the number of atoms or ions has to maintain that ratio, but only the number of sites. ...
... the number of atoms or ions has to maintain that ratio, but only the number of sites. ...
Full-text PDF - Verlag der Zeitschrift für Naturforschung
... an energetic material, the possible advantage resulting from introducing one further amino group to nitroguanidine is the generation of a larger gas volume when the compound is burned, which mainly is desired if the material is used in propellant systems. Apart from that, we also expect a higher hea ...
... an energetic material, the possible advantage resulting from introducing one further amino group to nitroguanidine is the generation of a larger gas volume when the compound is burned, which mainly is desired if the material is used in propellant systems. Apart from that, we also expect a higher hea ...
Hydrocarbons and Functional Groups
... 3. Name the branches based on how many carbons they have, and at what carbon they branch off of. 2-methyl-3-ethylheptane* *this is NOT the final name of this molecule 5. Put the branch names in alphabetical order. 3-ethyl-2methylheptane ...
... 3. Name the branches based on how many carbons they have, and at what carbon they branch off of. 2-methyl-3-ethylheptane* *this is NOT the final name of this molecule 5. Put the branch names in alphabetical order. 3-ethyl-2methylheptane ...
Electronic Supplementary Information (ESI) service
... Complex 8 was prepared by addition of a toluene solution (1 eq) of 5 (5 mol%) into a toluene solution of the complex PhPH2-BH3 cooled at -20°C. Evolution of hydrogen was immediately observed. The reaction was completed after one night to 0°C. Product is thermally unstable and should be kept in solut ...
... Complex 8 was prepared by addition of a toluene solution (1 eq) of 5 (5 mol%) into a toluene solution of the complex PhPH2-BH3 cooled at -20°C. Evolution of hydrogen was immediately observed. The reaction was completed after one night to 0°C. Product is thermally unstable and should be kept in solut ...
C E E ln − =
... Experimentally the anti form is 7.53 kJ/mol lower in energy. What is the equilibrium constant for their conversion ( ) at room temperature? C4H10 (anti) → C4H10 (gauge) Keq [Hints: the entropy change of this transformation is NOT equal to zero. Instead of determining ∆S directly, you should try t ...
... Experimentally the anti form is 7.53 kJ/mol lower in energy. What is the equilibrium constant for their conversion ( ) at room temperature? C4H10 (anti) → C4H10 (gauge) Keq [Hints: the entropy change of this transformation is NOT equal to zero. Instead of determining ∆S directly, you should try t ...
Main Menu - MsReenChemistry
... Each person is a carbon atom. You are only allowed to link hands or one leg with one, two or three people. Assume any open hands or legs are bonded to an imaginary hydrogen atom. How many different arrangements can you make? ...
... Each person is a carbon atom. You are only allowed to link hands or one leg with one, two or three people. Assume any open hands or legs are bonded to an imaginary hydrogen atom. How many different arrangements can you make? ...
I. Introduction to NMR spectroscopy
... What elements are commonly found in organic molecules? Which are suitable for NMR? element: ...
... What elements are commonly found in organic molecules? Which are suitable for NMR? element: ...
Hydroperoxide ion P.9 is much less basic than hydroxide ion P.10
... in each spin state on each atom, and the sum of the squares of all the c values on any one atom in all the molecular orbitals must also equal one. Thus the σ*-antibonding orbital of hydrogen will have c-values of 0.707 and –0.707, because these values make the whole set fit both criteria. ...
... in each spin state on each atom, and the sum of the squares of all the c values on any one atom in all the molecular orbitals must also equal one. Thus the σ*-antibonding orbital of hydrogen will have c-values of 0.707 and –0.707, because these values make the whole set fit both criteria. ...
Chapter 2: Alkanes Alkanes are molecules comprised of hydrogen
... Amines are classified according to the number of substituents bonded to nitrogen. Other functional groups are classified by the type of carbon they are attached to. ...
... Amines are classified according to the number of substituents bonded to nitrogen. Other functional groups are classified by the type of carbon they are attached to. ...
Single crystal structure determination using synchrotron X
... again into an inert one and to afford an acid-durable complex. TFE is known to be a weak acid and to donate a hydrogen bond, comparable to that of phenol, and a 1:1 complex of TFE and pyridine as an acid-base pair is reported. Therefore, we expected that the dissociated pyridyl moiety from the metal ...
... again into an inert one and to afford an acid-durable complex. TFE is known to be a weak acid and to donate a hydrogen bond, comparable to that of phenol, and a 1:1 complex of TFE and pyridine as an acid-base pair is reported. Therefore, we expected that the dissociated pyridyl moiety from the metal ...
HIGHLIGHTS OF NUCLEOPHILIC SUBSTITUTION REACTIONS
... b) occurs with formation of carbocation intermediates in the rate determining step c) involves one transition state per step. The rate-determining step involves a high polarity transition state d) follows first order (unimolecular) kinetics. That is, rate=k[substrate] In nucleophilic substitutions a ...
... b) occurs with formation of carbocation intermediates in the rate determining step c) involves one transition state per step. The rate-determining step involves a high polarity transition state d) follows first order (unimolecular) kinetics. That is, rate=k[substrate] In nucleophilic substitutions a ...
Organic Chemistry - City University of New York
... between a resonance hybrid in which the electrons are delocalized and the most stable one of its hypothetical contributing structures in which electrons are localized on particular atoms and in particular bonds. • One way to estimate the resonance energy of benzene is to compare the heats of hydro ...
... between a resonance hybrid in which the electrons are delocalized and the most stable one of its hypothetical contributing structures in which electrons are localized on particular atoms and in particular bonds. • One way to estimate the resonance energy of benzene is to compare the heats of hydro ...
Brominations and Alkene Synthesis CHM 233 Review
... actually, both will probably be formed!! Solution: use a very low concentration of Br2 to minimize direct reaction with the alkene ...
... actually, both will probably be formed!! Solution: use a very low concentration of Br2 to minimize direct reaction with the alkene ...
CHM 331 : General Organic Chemistry
... actually, both will probably be formed!! Solution: use a very low concentration of Br2 to minimize direct reaction with the alkene ...
... actually, both will probably be formed!! Solution: use a very low concentration of Br2 to minimize direct reaction with the alkene ...
DFT Studies of the Zinc Complexes of DNA Bases
... The optimized geometrical structures for Zn complexes of DNA bases are shown in Figure 1. The selected geometrical parameters for the optimized DNA bases and Zn complexes of these bases are summarized in Table 1. And the computed zinc cation association energies are shown in Table 2. As shown in Fig ...
... The optimized geometrical structures for Zn complexes of DNA bases are shown in Figure 1. The selected geometrical parameters for the optimized DNA bases and Zn complexes of these bases are summarized in Table 1. And the computed zinc cation association energies are shown in Table 2. As shown in Fig ...
a. b. c. d.
... couple and split each other into the triplets that are observed. 3. The CNMR is most helpful in a negative way: it has no peak in the carbonyl region (170210). ...
... couple and split each other into the triplets that are observed. 3. The CNMR is most helpful in a negative way: it has no peak in the carbonyl region (170210). ...
Ion exchange chromatography
... In cation exchange chromatography, raising the pH of the mobile phase buffer will cause the molecule to become less protonated and hence less positively charged. The result is that the molecule no longer can form a ionic interaction with the negatively charged solid support, which ultimately results ...
... In cation exchange chromatography, raising the pH of the mobile phase buffer will cause the molecule to become less protonated and hence less positively charged. The result is that the molecule no longer can form a ionic interaction with the negatively charged solid support, which ultimately results ...
III. Ionic Compounds
... C. Ionic Nomenclature Ionic Formulas Write each ion, cation first. Don’t show charges in the final formula. Overall charge must equal zero. If charges cancel, just write symbols. If not, use subscripts to balance charges. Use parentheses to show more than one polyatomic ion. ...
... C. Ionic Nomenclature Ionic Formulas Write each ion, cation first. Don’t show charges in the final formula. Overall charge must equal zero. If charges cancel, just write symbols. If not, use subscripts to balance charges. Use parentheses to show more than one polyatomic ion. ...
Exam 2 sample questions
... b) Compound III was synthesized from compound IV (reference: Tamura, O. et al, J. Org. Chem. 2005, 70, 10720). Show how this could be done. Hint: Compound IV is a cyclic hemiacetal, which is in equilibrium with its open-chain aldehyde form. A 5carbon chain present in both materials is in bold to aid ...
... b) Compound III was synthesized from compound IV (reference: Tamura, O. et al, J. Org. Chem. 2005, 70, 10720). Show how this could be done. Hint: Compound IV is a cyclic hemiacetal, which is in equilibrium with its open-chain aldehyde form. A 5carbon chain present in both materials is in bold to aid ...
Picosecond Flash Photolysis of Carbonyl Complexes ... Ruthenium(II} Porphyrin Cation Radicals
... spectroscopic properties of this species are consistent with a 'If' cation radical having a 2A 1u ground state. 7 Other axially coordinated ligands, such as 1m (Figure ID), result in spectra of the oxidized species that appear to be a more equal mixture of the 2A 2u and 2A 1u ground-state radicals. ...
... spectroscopic properties of this species are consistent with a 'If' cation radical having a 2A 1u ground state. 7 Other axially coordinated ligands, such as 1m (Figure ID), result in spectra of the oxidized species that appear to be a more equal mixture of the 2A 2u and 2A 1u ground-state radicals. ...
13C NMR Spectroscopy (#1d)
... C NMR spectra cover a wide range, from 0 to about 220 ppm, where carbonyl carbons are found. The degree of substitution on a carbon has about as much effect on its chemical shift position as does the presence of an electronegative atom. Generally, sp3-hybridized carbons appear between 8-60 ppm and s ...
... C NMR spectra cover a wide range, from 0 to about 220 ppm, where carbonyl carbons are found. The degree of substitution on a carbon has about as much effect on its chemical shift position as does the presence of an electronegative atom. Generally, sp3-hybridized carbons appear between 8-60 ppm and s ...
Chapter 10
... C-C single bonds are relatively unreactive due to large overlap of sp3 hybridized orbital and energy match, therefore very low HOMO and high LUMO energy ...
... C-C single bonds are relatively unreactive due to large overlap of sp3 hybridized orbital and energy match, therefore very low HOMO and high LUMO energy ...
2-Norbornyl cation
In organic chemistry, the term 2-norbornyl cation (equivalent with 2-bicyclo-[2.2.1]heptyl cation) describes one of the three carbocations formed from derivatives of norbornane. Though 1-norbornyl and 7-norbornyl cations have been studied, the most extensive studies and vigorous debates have been centered on the exact structure of the 2-norbornyl cation.The 2-norbornyl cation has been formed from a variety of norbornane derivatives and reagents. First reports of its formation and reactivity published by Saul Winstein sparked controversy over the nature of its bonding, as he invoked a three-center two-electron bond to explain the stereoselectivity of the resulting product. Herbert C. Brown challenged this assertion on the grounds that classical resonance structures could explain the stereospecificity without needing to adapt a new perspective of bonding.Evidence of the non-classical nature of the 2-norbornyl cation grew over the course of several decades, mainly through spectroscopic data gathered using methods such as Nuclear magnetic resonance (NMR). Crystallographic confirmation of its non-classical nature did not come until quite recently.The nature of bonding in the 2-norbornyl cation incorporated many new ideas into the field’s understanding of chemical bonds. Similarities can be seen between this cation and others, such as boranes.