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 2PtCl 4 with 2-acetyl pyridine thiosemicarbazone, HAcTsc. The new complexes, [Pt(AcTsc)Cl], [Pt(HAcTsc) 2]Cl 2 and [Pt(AcTsc) 2], have been characterized by elemental analyses and spectroscopic studies. The crystal structure of the complex [Pt(AcTsc)Cl] 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–Cl), π–π and weak Pt–Pt and Pt–π 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(II) complexes, [Pd(AcTsc)Cl], [Pd(HAcTsc) 2]Cl 2 and [Pd(AcTsc) 2], 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) 2] and [Pd(AcTsc) 2] 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.