ANALYSIS OF THE EFFECT OF THE ELECTRONIC-STRUCTURE OF THE CL ATOM IN COMPLEXES OF CHLORIDES OF GROUP IV ELEMENTS ON CL-35 NQR FREQUENCY ANDASYMMETRY PARAMETER

Analysis of changes in Cl-35 NQR frequency of complexes MCl(4).L and M Cl(4).2L for M = Si, Ge, Sn and Ti was performed. The population of th e atomic orbitals was calculated by the quantum chemistry methods PM3 and INDO. The results provided an explanation of the changes in Cl-35 NQR frequency and the asymmetry parameter upon complex formation. In t he complexes of non-transition elements, a decrease in Cl-35 NQR frequ ency is first of all related to increasing population of p(z) orbitals on Cl atoms. In the complexes of Ti, the increase in Cl-35 NQR freque ncy depends on a decrease in the p(pi) to d(pi) electron density trans fer.