Synthesis and Structural Characterization of Zn(II) and Co(III) Complexes of Picolinoyl(4-ethylthiosemicarbazide)

Abstract

Reaction of ZnCl2 and two equivalents of picolinoyl(4-ethylthiosemicarbazide), HL, in MeOH in the presence of a supporting base like Et3N results in the neutral complex [Zn(L)2] (1). A similar reaction of CoCl2, however, brings about a cobalt(III) cationic complex, which could be separated as its chloride salt [Co(L)2]Cl (2). The spectroscopic studies and X-ray structure analyses indicate that in 1 and 2, the metal ions are octahedrally coordinated by two (Npyridine, S, N1) chelates belonging to two singly deprotonated tridentate ligands {L–}.