Molecular modeling of some calcium and magnesium ionic bridges

Abstract

Bond length and atomic charges are calculated for L2M and L 2M2+ complexes, as well as dissociation energies in vacuum for the complexes, with semiempiric ZINDO1 and PM3 methods, and with ab initio method with 3-21G and 6-31G* basis sets. Here, L are CH 3COO-, CH3OSO3-, ethylenediol and 1,4-dioxane; M2+ are Ca2+ and Mg 2+. Geometries for CH3COO- and 1,4-dioxane are in fair agreement with X-ray crystallographic data. Dissociation energies calculated by ab initio, are in the range of 200-500 kcal/mol, generally larger for Mg2+ then for Ca2+-complexes. © 2006 Wiley Periodicals, Inc.