Semi-empirical (PM3) calculations on beta-diketones and their Zn-II complexes

Semi-empirical calculations on beta-diketones (acetylacetone, benzoylacetone and dibenzoylmethane) and their Zn-II complexes Zn(acac)(2), Zn(acac)(bzac), Zn(bzac)Z, Zn(acac)(dbzm) and Zn(bzac)(dbzm) have been carried out using PM3 method with the help of MOPAC 6.0 program. The values for the heats of formation, total energies, ionization potentials, atom electron densities, atomic charges, bond lengths and bond angles have been determined and optimized geometries have been worked out. The heats of formation are -117.0306 to -6.3592 kcal, total energies are -4469.3733 to -2602.5726 eV and ionization potentials are 8.9802 to 9.1501 eV. Atom electron densities on the oxygen atoms surrounding zinc atom are 6.2991 to 6.3187 and atomic charges are -0.3187 to -0.2991. Zn-O bond lengths are in the range 1.9796 to 2.0348 angstrom. O-Zn-O bond angles are close to 109.5 degrees (99.1724 degrees to 122.7135 degrees) supporting distorted tetrahedral geometry for the complexes.