Insights to the strained thiocarbamate derivative complexes of platinum group metals induced by azide as a co-ligand: Characterization and biological studies

Abstract

Halide bridged metal precursors of platinum group on reaction with thiocarbamate derivative ligands (L1 and L2) yielded a series of neutral mono-dentate complexes (1–6) formulated as [(arene)M(κ1(S)-L)Cl2] where, L = L1 and L2, M = Ru, Rh and Ir, arene = p-cymene, Cp∗. Structural studies revealed the ligands coordinated to the metal centers through the thione sulfur in a mono-dentate fashion. These neutral complexes (1–6) were further reacted with NaN3 in methanol which resulted in the formation of highly strained κ2(N,S) azido complexes (7–12). Further treatment of the azido complexes with diethyl acetylene dicarboxylate (DEAD) yielded in the case of rhodium and iridium triazolo complexes (13–16). All these complexes were characterized by various spectroscopic techniques. NMR analysis revealed the triazolo ring coordinated to the metal center via the central nitrogen. Besides the varied coordination of the complexes, these complexes as well as the ligands exhibited antibacterial activity against some bacterial strains under study as well as profound antioxidant potency.