THE APPLICATION OF THE DENSITY MATRIX METHOD FOR THE INVESTIGATION OF THE TRANS-EFFECT OF HETEROATOM IN SIGMA-ELECTRON SYSTEMS

摘要

The dependence of the intramolecular charge transfer through the sigma-electron systems of substituted hydrocarbons on the spatial arrangement of the X-C-alpha and C-beta-C-gamma bonds has been studied using the perturbation theory for the one-electron density matrix (DM). Analytical expressions for the populations of the orbitals pertinent to the cis- and Irans-bonds with respect to the X-C-alpha bond have been obtained and analyzed. The Hamiltonian matrix elements determining the predominant direction of the above-defined charge transfer (cis or tuans) have been revealed. The electron-accepting and electron-donating substituents (X) have been considered separately and the dependence of the resulting charge-transfer direction on the properties of substituent has been established. (C) 1996 John Wiley & Sons, Inc. [References: 17]