ISSN:
0020-7608
Keywords:
atomic charge
;
isotropic shielding
;
IGLO method
;
bond orbital
;
bond dipole moment
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The problem of defining a reliable quantum mechanical charge by comparison with one-electron properties is analyzed, and it is stressed that properties involving the virtual space are not suited to that end. Particular attention is devoted to the relationship between charges and chemical shifts for the case of saturated hydrocarbons. A simple explanation of the Grant and Paul α effect is suggested, which can also account for the modified population analysis proposed by Fliszár. Moreover the vexata quaestio of the direction of the C—H bond dipole moment has been reexamined. The awkward theoretical prediction (C+—H-) can be reconciled with the one based on experimental data and electronegativities (C-—H+) if one considers that the former is determined by an hydridization contribution to the dipole moment, which tend to cancel in a summation over all the bonds formed by each atom. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 68: 201-210, 1998
Type of Medium:
Electronic Resource
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