Biological activity of Co(III) and Ni(II) complexes of pyridine-2-carbaldehyde N(4)-methylthiosemicarbazone: Synthesis, characterization, crystal structure of Co(III) complex of pyridine-2-carbaldehyde N(4)-methylthiosemicarbazone1

Abstract

Transition metal complexes formulated as [Co(L)2]ClO4 (I) and [Ni(L)2] · H2O (II), where HL = pyridine-2-carbaldehyde N(4)-methylthiosemicarbazone, have been synthesized. Complex I was characterized by elemental analysis, IR, MS and single-crystal X-ray diffraction studies. In complex I, the ligand is N2S tridentate, coordinating to the metal center through pyridine nitrogen, imine nitrogen and sulfur atoms. Hydrogen bonds link the different components to stabilize the crystal structure. Preliminary in vitro screening indicated that the free ligand was active against various bacteria and fungi and all the tested compounds showed significant antitumor activity against K562 leukaemia cell line, and can therefore be candidates for further stages of screening in vitro and/or in vivo.