Geometry optimization and thermodynamic stabilities of mixed ligand complexes [Co(beta-diketone)(L)(H2O)(2)]

For the mixed ligand complexes [Co(beta-diketone)(L)(H2O)(2)] (where beta-diketone = pentane-2,4-dione, 1-phenylbutane-1,3-dione, 1,3-diphenylpropane-1,3-dione and L = 2-hydroxybenzaldehyde, 1-(2-hydroxyphenyl)ethanone, 1-(2-hydroxyphenyl)propan-1-one) computational analysis has been carried out with the help of software MOPAC 2006 using PM3 method and various parameters such as heats of formation, total energies, ionization potentials, atom electron densities, atomic charges, bond lengths and bond angles have been determined. All the mixed ligand complexes are thermodynamically stable as evidenced by heats of formation. Atom electron density data suggest coordination to metal atom through oxygen atoms of the ligands. Optimized geometries have been worked out which support octahedral geometry for the complexes.