Synthesis, characterization and biological activities of organotin(IV) diallyldithiocarbamate complexes

Organotin(IV) complexes represented as R2SnL2 (where R = Cl, CH3, C4H9, C6H5; L = N,N-diallyldithiocarbamate) have been synthesized and characterized by elemental analysis, H-1, C-13, Sn-119 NMR and FTIR spectroscopic analyses. The structures of [(CH3)(2)SnL2] and [(C4H9)(2) SnL2] were further determined using single crystal X-ray crystallography. These complexes crystallized in a triclinic crystal system with P-1(2) space group. Two N,N-diallyldithiocarbamato ligands bond to the tin(IV) ion in an anisobidentate fashion resulting in a highly distorted six coordinate geometry, best described as skew trapezoidal-bipyramidal geometry. Results obtained for the antimicrobial study showed a varied activity against some Gram (+) and (-) bacterial and fungi species. This activity generally ranged from moderate to good in which complex [(C6H5)(2)SnL2] and [(C4H9)(2)SnL2] exhibited the best antimicrobial properties. The 2,2-dipheny1-1-picrylhydrazyl (DPPH) radical scavenging ability and reducing power studies showed that complex [(CH3)SnL2] displayed the highest antioxidant activities compared to the other compounds but a little less than the standard, gallic acid. Furthermore, the cytotoxicity study against the human tumour cell line (HeLa) showed a varied activity due to lipophilicity and selectivity of the cell line towards the complexes. This observed activity compared favourably with the standard drug (5-FU) used in which complex [(C6H5)(2)SnL2] was found to show a better cytotoxic activity than the standard drug.