Synthesis and spectroscopic characterization of mononuclear/binuclear organotin(IV) complexes with 1H-1,2,4-triazole-3-thiol: Comparative studies of their antibacterial/antifungal potencies

Abstract

A series of di and triorganotin(IV) complexes of the general formula, R2(Cl)SnL (R= Me: 1; Bu: 2) and R3SnL (R = Bu: 3; Ph: 4) have been synthesized by refluxing equivalent molar ratios of orgnotin(IV) chlorides (R2SnCl2/R3SnCl) with the 1H-1,2,4-Triazole-3-thiol (LH) in dry methanol. The synthesized complexes (1-4) were further treated with CS2 and R2SnCl2/R3SnCl in 1:1:1 molar ratio to yield the homobimetallic complexes of the types R2(Cl)SnLCS2Sn(Cl)R2 (R = Me: 5; Bu: 6) and R3SnLCS2SnR3 (R = Bu: 7; Ph: 8). The ligand and the complexes have been characterized by elemental microanalysis (CHNS), FT-IR and multinuclear NMR (1H&13C), and electron ionization mass spectrometry. IR data demonstrates that the dithiocarbamate donor site of the ligand acts in a bidentate manner and there isa trigonal bipyramidal geometry around Sn(IV) in solid state. 1H and 13C NMR data supports the tetrahedralgeometry with thiol donor sites of the ligand while tetra and penta coordinated environments around dithiocarboxylate bound tin(IV) in solution state. Mass spectrometric data supported well the structures of the synthesized complexes. The homobimetallic derivatives were found more active than mononuclear organotin(IV) compounds and free ligand against various strains of bacteria and fungus.