Syntheses, characterization, X-ray diffraction studies and in vitro antitumor activities of diorganotin(IV) derivatives of bis(p-substituted-N-methylbenzylaminedithiocarbamates)

Six new organotin(IV) dithiocarbamate complexes of the type R2SnL2, where (L = p-bromo-N-methylbenzylaminedithiocarbamate and p-fluoro-N-methylbenzylaminedithiocarbamate, and R = dimethyl-, dibutyl- and diphenyl-) have been synthesized in good yields. The isolated ligands and their respective diorganotin complexes were suitably characterized by elemental analysis, FT-IR, 1 H, 13 C and 119 Sn NMR spectroscopies. The crystal structures of three diorganotin(IV) complexes have been determined by X-ray crystallography. The spectroscopic and single crystal X-ray diffraction data illustrate that the dithiocarbamato ligands in the dimethyltin(IV) and diphenyltin(IV) derivatives 1, 2 and 6 are monodentate and the geometry at tin is best described as a distorted tetrahedron. The dimethyltin(IV) and dibutyltin(IV) compounds were evaluated for their in vitro antiproliferative activities. The dibutyltin(IV) complexes showed moderate cytotoxicities toward human leukemic lymphoblastoma Jurkat cells, lymphoblastoma K-562 cells, hepatoblastoma HepG2 cells and mouse fibroblast L929 cells.