SYNTHESIS, SPECTROSCOPIC AND STRUCTURAL CHARACTERIZATION, AND BIOLOGICAL-ACTIVITY OF AQUACHLORO(PYRIDOXAL THIOSEMICARBAZONE) COPPER(II) CHLORIDE

The synthesis, spectroscopic studies, x-ray crystal structure, and biological properties of the complex [Cu(H(2)L)(OH2)Cl]Cl (1) (H(2)L = pyridoxal thiosemicarbazone) are reported. The compound crystallizes in space group P2(1)/n, a = 12.128(2), b = 9.096(2), c = 13.592(2) Angstrom, beta = 108.65(2)degrees, U = 1420.7 Angstrom(3), and Z = 4. The molecular structure consists of discrete cations [Cu(H(2)L)(OH2)Cl](+) and Cl- anions. Each copper atom is in an approximately square pyramidal environment involving the phenolic oxygen, the imine nitrogen, the sulphur, and a water oxygen in the equatorial positions, while a chlorine atom occupies the axial position. The structure of this complex is compared to that of the dimeric [{Cu(HL)(OH2)}(2)]Cl-2.2H(2)O (2) obtained under different experimental conditions, to that of a Co(III) complex with the same ligand [Co(HL)L] 4.5H(2)O (3) and to that of the free ligand H(2)L, especially in relation to its biological activity. Compounds 1 and 2 have not antiviral action in vitro with respect to RNA viruses, show an inductive effect on Friend erythroleukemia cells (FLC), erythroid differentiation and a suppressive effect regarding FLC proliferation. Complex 3 and the free ligand do not have biological activity.