ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Extensively optimized Lewis orbital (Frost model) structures are reported for CH3N, CH3NH+, CH3CH, CH3CH2+, CH3BH2, CH2NH, and CH2NH2+ (spiro and planar). Electronic energy differences between these isoelectronic species were estimated by the integral Hellmann-Feynman (iHF) formula, with the hope that satisfaction of the Hellmann-Feynman conditions would lead to accurate iHF values of energy changes. We observed a strongly nonlinear relation between the iHF error and the departure of the overlap of wave-functions of the structures from unity. MO computations in common orbital (not determinantal) basis sets for CH3NH+—CH2NH2+ (planar), CH3N—CH2NH, and CH3CH—CH2CH2 produced greatly improved iHF estimates of energy changes, reducing errors by as much as 80 times. Certain features of the static optimum structures and the transition densities suggested that the syn path for rearrangement of methyl carbene to ethylene is a general feature of rearrangements in these systems.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560100104
