Synthesis, characterization and cytotoxic activity of new diorganotin(IV) complexes of N‐(3,5‐dibromosalicylidene)tryptophane

Four new diorganotin(IV) complexes of N-(3,5-dibromosalicylidene)tryptophane, R2Sn[3,5-Br2-2-OC6H2CHNCH(CH2Ind)COO] [Ind = 3-indolyl; R = Et (1); n-Bu (2); Cy (3); Ph (4)], were synthesized and characterized by elemental analysis and IR, NMR (1H, 13C and 119Sn) spectra. The crystal structures of complexes 1–3 were determined by X-ray single crystal diffraction. The tin atom is five-coordinated and its coordination geometry is best described as an intermediate between trigonal bipyramidal and square pyramidal. Intermolecular weak interactions in the complexes 1–3 connect molecules into a one-dimensional helical chain and a two-dimensional array. The dibutyltin complex 2 has potent in vitro cytotoxic activity against two human tumor cell lines, CoLo205 and Bcap37, while the diethyltin complex 1 displays weak cytotoxic activity. Copyright © 2011 John Wiley & Sons, Ltd.