Zinc(II) Complexes of Acetophenone and 5-Chloro-2-hydroxy-benzophenone Thiosemicarbazones. Synthesis, Characterization, and Nonlinear Optical Properties from Quantum Chemical Calculations

Abstract

A number of mixed ligand complexes of zinc(II) with acetylacetone, acetophenone thiosemicarbazone, and 5-chloro-2-hydroxy-benzophenone thiosemicarbazone ligands were synthesized. The complexes [Zn(L)(acac)(2)] were characterized by elemental analysis as well as by IR and H-1 NMR spectroscopy. The structure of the zinc(II) complex of acetophenone thiosemicarbazone (1) was determined by single crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P21/c with Z = 4. In vacuo geometry optimization and electronic calculation have been performed using Density Functional Theory (DFT) without any symmetry constraints for the compounds. Experimental and calculated data indicated that the thiosemicarbazone ligand acts as monodentate ligand through the sulphur atom and the complex adopts distorted square-pyramidal geometry, which consists of the sulphur atom and four oxygen atoms of the acetylacetone moieties. Polarizability (alpha), first hyperpolarizability (beta), frontier orbital energies, and dipole moment (mu) are also reported for ligands L-1, L-2, and complexes 1 and 2.