THE ELECTRONIC AND ENERGY CHARACTERISTICS OF THE M-O BOND IN MODEL COMPLEXES M(MAL)(2) (M=MG2+, CA2+, SR2+, AND BA2+)

The DV X-alpha method is used to calculate M-O bond energies, atomic c harges, and orbital overlap populations for the model complexes M(Mal) (2) (M = Mg2+, Ca2+, Sr2+, and Ba2+) using the sp basis set with the a ppraisal vacant np or (n - 1)d atomic functions of M. The metal-ligand bond is shown to have an ionic character, with the small contribution of the covalence decreasing from Mg to Ba. The charge transfer from t he metal to the ligand is governed by the ionization potential of the M atom. The vacant M np and (n - I)d atomic orbitals are not involved in the formation of the M - O bond.