Approaches to charge calculations in molecular mechanics

Journal of Computational Chemistry - Tập 3 Số 3 - Trang 407-416 - 1982
Raymond J. Abraham1, Lee Griffiths2, Philip Loftus3
1The Robert Robinson Laboratories, University of Liverpool, Liverpool L69 3BX, England
2I.C.I. (Mond Division), P.O. Box 8, The Heath, Runcorn, Cheshire, England
3Stuart Pharmaceuticals, Wilmington, Delaware 19897

Tóm tắt

Abstract

Alternative methods of estimating atomic charges in haloalkanes are presented, derived from quantum mechanical and classical treatments. A scheme based on a breakdown of the transmission of charge by polar atoms into one‐bond, two‐bond, and three‐bond additive contributions is given, in which the one‐bond effect is proportional to the difference in the electronegativities of the bonded atoms, and the two‐ and three‐bond effects functions of the atomic electronegativity and polarizability. Suitable developments of the basic scheme, including an iterative self‐consistent process, give calculated dipole moments for a variety of haloalkanes in good agreement with the observed values. The atomic charges obtained by this scheme are compared with other estimates of these charges. They are similar to those derived from a simple LCAO–MO scheme but differ from those obtained by population analysis of more refined quantum mechanical calculations.

Từ khóa


Tài liệu tham khảo

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Thông tin xuất bản

Journal of Computational Chemistry

Tập 3 Số 3

407-416

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