Mononuclear indolyldithiocarbamates of SnCl4 and R2SnCl2: Spectroscopic, thermal characterizations and cytotoxicity assays in vitro

Several mononuclear Sn compounds ranging from mono to tetrakisindoline dithiocarbamates have been synthesized and characterized. Various spectroscopic techniques in combination with microanalytical data lead to the formation of 1:2 and 1:4 (Sn:Naindtc) type complexes depending on the molar ratio of the sodium salt of indolinedithiocarbamate employed. A symmetrical bidentate coordination of the indolinedithiocarbamate has been observed in all the cases as evident by a single sharp band at 1000 cm⁻¹ in their IR spectra. The compounds were found to adopt an octahedral arrangement around the Sn atom as evident from their ¹¹⁹Sn NMR data. The TGA/DSC profile of the ligand exhibits a two-stage thermogram while the complexes decompose in three steps leading to the formation of tin-sulfide as the eventual end product. The in vitro cytotoxicity of butyl and phenyl analogues has been studied against the standard human tumor cell lines. The compounds have also been screened for their antifungal and antibacterial activity against E. coli, S. aureus, C. albicans and A. flavus. The results indicated the compounds to be active.