Platinum(II) complexes with 2-acetyl pyridine thiosemicarbazone - Synthesis, crystal structure, spectral properties, antimicrobial and antitumour activity

An interesting series of new platinum complexes has been synthesized by the reaction of Na(2)ptCl(4) with 2-acetyl pyridine thiosemicarbazone, HAcTsc. The new complexes, [Pt(AcTsc)CI], [Pt(HAcTsc),]Cl-2 and [Pt(AcTsc)(2)], have been characterized by elemental analyses and spectroscopic studies. The crystal structure of the complex [Pt(AcTsc)CI] has been solved by single-crystal X-ray diffraction. The anion of HAcTsc coordinates in a planar conformation to the central platinum(II) through the pyridyl N, azomethine N and thiolato S atoms. Double intermolecular hydrogen bonds (NH-CI), pi-pi and weak Pt-Pt and Pt-pi contacts lead to aggregation and to a two-dimensional supramolecular assembly. The antibacterial and antifungal effect of the novel platinum(II) complexes and the related palladium(fl) complexes, [Pd(AcTsc)CI], [d(HAcTsc),]Cl, and [Pd(AcTsc),], were studied in vitro. The complexes were found to have a completely lethal effect on Gram+ bacteria, while the same complexes showed no bactericidal effect on Gram- bacteria. Additionally, the complexes [Pt(AcTsc),] and [Pd(AcTsc),] showed effective antifungal activity towards yeast. Among these compounds [33], the most effective in inducing antitumour and cytogenetic effects are the complexes [Pt(AcTsc)(2)] and [Pd(AcTsc)(2)] while the rest, display marginal cytogenetic and antitumour effects. (C) 2001 Elsevier Science BY All rights reserved.