Interaction of organotin with piperazine derived self-assembled cylindrical bisdithiocarbamates: Spectral and thermal investigations

Few organotin complexes of the type R4Sn2L2 where R = CH3 (2), C4H9 (3), C6H5 (4), and Sn2L2Cl4 (5) (L = bis(2,2′-dithiopiperazinato-2,2′-diaminodiethylamine)) have been synthesized and suitably characterized by FT-IR, UV–vis, 1H NMR, 119Sn NMR, ESI-MS, TGA/DSC, microanalysis and room temperature molar conductivity data. On the basis of FT-IR spectral studies, a symmetrical bidentate coordination has been proposed for all the complexes while the absence of any higher peak in the ESI-MS may be corroborated with the formation of binuclear complexes. On the basis of 119Sn NMR spectroscopy, six-coordinate geometry has been observed for the Sn-center in all the complexes. The TGA/DSC profile of the complexes implies their higher stability than its precursor. However, on the basis of IDT values the stability order of the organotin complexes was found to be 4 > 3 > 2. The room temperature conductivity values of the 1 mM solution of the ligand and its complexes are found to be comparable with that of non-ionic complexes.