STUDY OF HYDROGEN-BONDING ABILITY OF ORGANIC-MOLECULES USING ELECTROSTATIC POTENTIAL AND ELECTRIC-FIELD MAPPING - ROLE OF HYBRIDIZATION DISPLACEMENT CHARGE

Molecular electrostatic potential (MEP) and molecular electric field ( MEF) maps of certain organic compounds were studied using optimised Hy bridization Displacement Charge (HDC)-corrected Lowdin charges and Mul liken charges obtained using the Modified Neglect of Diatomic Differen tial Overlap (MNDO) method. The MEP minimum values computed by distrib uting the optimised HDC- corrected Lowdin charges according to the for ms of squares of the corresponding valence s Slater atomic orbitals co ntinuously in three dimensions were found to correlate linearly with t heir hydrogen bond accepting and donating abilities. The average MEF v alues near the appropriate sites on the van der Waals surfaces of the molecules were also found to correlate linearly with their hydrogen bo nd accepting abilities of molecules. Further, the MEP and MEF values c omputed using optimised HDC-corrected Lowdin charges were found to pro vide much better linear correlations with the observed hydrogen bond f orming abilities of the molecules than those obtained using Mulliken c harges.