The relative energies of the chair and boat transition states of a variety of Ireland-Claisen rearrangements were obtained by B3LYP/6-31G calculations. Theoretical results are in good agreement with experimental data and provide a quantitative analysis of the origins of boat preferences that are observed in some of these reactions.

Quantum mechanical ab initio UHF, MP2, MC-SCF and DFT calculations with moderate Gaussian basis sets were performed for MnX6, X = H2O, F, CN, manganese octahedral complexes. The correct spin-state of the complexes was obtained only when the counter ions neutralizing the entire complexes were used in the modelling at the B3LYP level of theory.

B3LYP/6-31+G(d) calculations of structures and relative energies for competing transition states for intramolecular Diels-Alder reactions of substituted 3,5-hexadienyl acrylates and acrylamides show that boatlike conformations are sometimes favored in the forming ring that includes the tether.

benzyl chloride and tin powder were used to prepare dibenzyltin dichloride according to a literatureprocedure. in this study, ir spectroscopy, homo-lumo energy gap, nbo analysis, polarizability,some geometrical parameters, natural charge and electrical potential of atoms, global hardness,electronic chemical potential, global electrophilicity index, and molar volume of dibenzyltindichloride were...

The low-lying electronic states of Ga2N, GaN2 and the corresponding anions and cations have been investigated using B3LYP, MP2, CCD, complete active space multi-configuration self-consistent field technique (CASSCF) and multi-reference singles + doubles configuration interaction (MRSDCI) calculations. Potential energy surfaces, geometries, energy separations, adiabatic ionization energies, elec...

Herein we describe our search for a carbocation with a delocalized 5-center 4-electron C- - -H- - -C- - -H- - -C bonding array. Various helical and polycyclic molecular architectures were explored using B3LYP calculations, ultimately leading to cation 8, a remarkable species that possesses two trigonal pyramidal carbons flanking a five-coordinate trigonal bipyramidal carbon.

In this work, regular convergence patterns of the structural, harmonic, and VPT2-calculated anharmonic vibrational parameters of ethylene towards the Kohn-Sham complete basis set (KS CBS) limit are demonstrated for the first time. The performance of the VPT2 scheme implemented using density functional theory (DFT-BLYP and DFT-B3LYP) in combination with two Pople basis sets (6-311++G** and 6-311...

There is a growing interest in probing the mechanism of catalytic transformations effected by non-heme iron-oxo complexes as these reactions set a platform for understanding the relevant enzymatic reactions. The ortho-hydroxylation of aromatic compounds is one such reaction catalysed by iron-oxo complexes. Experimentally [Fe(II)(BPMEN)(CH3CN)2](2+) (1) and [Fe(II)(TPA)(CH3CN)2](2+) (2) (where T...

One main group of organic chemistry is related to the aromatic compounds. In the present work, we replaced the CH group of benzene by silicon and nitrogen analogues. Then, Density functional theory (DFT) calculations were carried out for six-membered heterocyclic Si-N aromatic rings. Full geometry optimizations were performed in gas-phase, and at B3LYP level using 6-311++G(d,p) and CBSB7 basis ...