Stereoelectronic structure of MCl4-benzoyl chloride (M=Si, Ge, Sn) systems resulting from ab initio calculations and NQR 35Cl

Abstract

Results of quantum-chemical calculations of MCl4–C6H5COCl (M=Si, Ge, Sn) systems of 1 : 1 composition using RHF/3-21 G* and MP2/3-21 G* levels as well as those of 1 : 2 composition using the RHF/3-21 G* level have been represented. MCl4 ← C6H5COCl complexes of 1 : 1 composition are energetically more advantageous. They are formed in solid state provided that the M···O distance in individual systems is considerably less than the sum of van der Waals radii of M and O and their total energies are appreciably less than the sum of total energies of components. These conditions are realized only for M=Sn. In systems of 1 : 2 compositions, calculated M···O distances are practically equal to the sum of covalent radii of M and O. Nonetheless, complexes with such composition are not formed in solid state. Total energy of the system which is lower than the sum of its components’ energies is not an indispensable condition for complex formation. The 35Cl nuclear quadrupole resonance (NQR) frequencies and asymmetry parameters of the electric field gradient at the 35Cl nuclei have been evaluated using the results of ab initio calculations.