Author(s): Toubin C; Yeung DY; English AM; Peslherbe GH;
The degradation of S-nitrosothiols (RSNOs) to release NO is believed to be catalyzed by CuI ions, but the mechanism remains unclear. Kinetic experiments have shown that decomposition rates vary significantly with the chemical nature of the RSNO considered. On the basis of first-principles calculations, the catalytic role of CuI ion is investigated for the ...
Article GUID: 12475301
Author(s): Qadir K Timerghazin
First-principles molecular dynamics simulations of the excited-state dynamics of I-(H2O)3 have been performed to gain some insight into the general features of the relaxation process of photoexcited I-(H2O)n clusters. The relaxation of excited I-(H2O)3 is characterized by rapid motion of water molecules and slow recoil motion of the iodine atom. Both solv ...
Article GUID: 12914436
Author(s): Robert C Mawhinney
A combination of density-functional theory and natural resonance theory has been used to show that a complete description of the electronic structure of nitrilimines, R(1)CNNR(2), requires four resonance structures (propargylic, allenic, 1,3-dipolar and carbenic); appropriate substituents were shown to enhance the carbene character of nitrilimines to the ...
Article GUID: 15306921
Author(s): Paul G Loncke
Substituent effects and the role of negative hyperconjugation in 1,2-silyl migration and decarbonylation of methoxy(substituted-siloxy)carbenes have been investigated using quantum chemical calculations and natural bond orbital analysis. It has been found that sigma-electron-withdrawing substituents generally lower the barriers for 1,2-silyl migration and ...
Article GUID: 15917909
Author(s): Lei Zhang
Vertical excitation energies for electronic transitions from the ground state to the first two excited states of phenol, mono- and disubstituted methoxyphenols and methyl-substituted phenols have been characterized with the Time-Dependent Density Functional Theory (TD-DFT), the Complete Active Space Self-Consistent Field method (CASSCF) and the Coupled Cl ...
Article GUID: 16313201
Author(s): Denise M Koch
We have investigated the photodissociation dynamics of NaI(H(2)O)(n) [n = 1-4] clusters using the molecular dynamics with quantum transitions method and a quantum mechanics/molecular mechanics description of NaI(H(2)O)(n), which involves a semiempirical valence-bond approach to describe the NaI electronic structure and classical solvent-solvent and solute ...
Article GUID: 16435804
Author(s): Pascal Larrégaray
The unimolecular dissociation dynamics of aluminum clusters following collision with either a rare gas atom or a surface is investigated by classical trajectory simulations with model potentials. Two conformers of Al(6) with very distinct shapes, i.e., the spherical O(h) and planar C(2)(h) clusters, are considered in this work. The initial vibrational ene ...
Article GUID: 16435829
Author(s): Qadir K Timerghazin
High-level ab initio calculations employing the multireference configuration interaction and coupled clusters methods with a correlation-consistent sequence of basis sets have been used to obtain accurate potential energy curves for the complex of the sodium cation with the iodine atom. Potential curves for the first two electronic Lambda-S states have ve ...
Article GUID: 16438589
Author(s): Grygoriy Dolgonos
The potential stabilization of normally unstable C20, the smallest fullerene, via its encapsulation inside a tetraureacalix[4]arene dimer has been analyzed using molecular mechanics calculations with different force fields, the self-consistent-charge density-functional tight-binding with dispersion correction (SCC-DFTB-D) model, and standard density-funct ...
Article GUID: 16869690
Author(s): Grygoriy A Dolgonos
The C2 fragmentation energies of the most stable isolated-pentagon-rule (IPR) isomers of the C80 and C82 fullerenes were evaluated with second-order Møller-Plesset (MP2) theory, density-functional theory (DFT) and the semiempirical self-consistent charge density-functional tight-binding (SCC-DFTB) method. Zero-point energy, ionization energy and empirical ...
Article GUID: 17588181
Author(s): Qadir K Timerghazin
A resonance representation of the electronic structure of S-nitrosothiols as a combination of the conventional R-S-N=O structure, a zwitterionic structure R-S+=N-O-, and a RS-/NO+ ion pair is proposed. The resonance forms are employed to predict and rationalize the structural and conformational properties of RSNOs, their interaction with Lewis acids, and ...
Article GUID: 17616141
Author(s): Qadir K Timerghazin
Two or more polar molecules can trap an excess electron either in a dipole-bound fashion where it is located outside of the cluster (dipole-bound electron) or inside the cluster (solvated electron). The topology of the electron density in dipole-bound and solvated-electron clusters has been examined for the paradigm (HF)3- cluster. As spatial confinement ...
Article GUID: 17705589
