Modified Hybridization Displacement Charge Scheme for #pi#-Electron Systems: Study of Molecular Electrostatic Potential Maps

摘要

A modified form of the hybridization displacement charge scheme (HDC-PI) suitable for application to molecules where #pi#-electrons play the dominant role in controlling molecular electrostatic potential (MEP) features is presented. This modified scheme does not only preserve the atomic contributions to molecular dipole moment but also it represents the two opposing components of atomic hybridization dipole moment arising due to #pi#-electrons, one due to the #pi#-electrons located above the molecular plane and the other due to those located below the plane, so as to reproduce MEP features appropriately. The method has been applied within the framework of AMl and MNDO methods to several different types of molecules containing #pi#-electrons demonstrating its very satisfactory performance.