Synthesis, spectral, molecular modeling, thermal analysis studies of orange (II) complexes

Abstract

Six Orange (II) metal complexes of Mn (II), Fe (III), Co (II), Ni (II), Cu (II) and Zn (II) were prepared and characterized by elemental analysis, IR, electronic spectra and magnetic susceptibility. The complexes were of different geometries: Octahedral and Tetrahedral. ESR was studied for copper complex. The prepared complex was of isotropic nature. Molecular modeling calculations were used to characterize the ligation sites of the free ligand. Furthermore, quantum chemical parameters of Orange (II) such as the energies of highest occupied molecular orbital (EHOMO), energies of lowest unoccupied molecular orbital (ELUMO), the separation energy (ΔE = ELUMO − EHOMO), the absolute electronegativity, χ, the chemical potential, Pi, the absolute hardness, η and the softness, σ, were obtained for Orange (II). The thermal analyses of the complexes were studied by DTA, TGA and DSC techniques. The thermodynamic parameters, thermolysis and the thermal transitions, such as glass transitions, crystallization and melting temperatures for ligand and its complexes were evaluated and discussed. The entropy change values, ΔS#, showed that the transition states are more ordered than the reacting complexes. Biological activity for Orange (II) and its complexes were done.