Synthesis, characterization, crystal structure and antitumor activity of organotin(IV) compounds bearing ferrocenecarboxylic acid

Four new organotin(IV) complexes [(Bu3Sn)(FcCOO)]n (1), [(μ-Bu2Sn)2(μ-Bu2SnFcCOO)2(μ3-O)2(μ-OCH3)2]2 (2), [Ph3Sn(FcCOO)(H2O)](phen) (3) and [{Ph3Sn(FcCOO)}2(4,4′-bipy)] (4) [Fc = (η5-C5H5)Fe(η5-C5H4)] have been synthesized and characterized by elemental analyses, IR, (1H and 13C) NMR spectra and X-ray single-crystal diffraction analyses. The structure analyses show that all tin atoms in complexes 1–4 are five-coordinated with trigonal bipyramid geometry. Complexes 1–4 and FcCOOH undergo reversible one-electron oxidations in methanol solution. The antitumor activities of complexes 1–4 have also been tested. Complexes 1 and 2 exhibit medium activity towards P388 cell lines and Hela cell lines. Complexes 3 and 4 exhibit medium activity towards P388 cell lines but strong activity towards Hela cell lines. This may result from complexes 3 and 4 including the neutral molecules 1,10-phenanthroline and 4,4′-bipy.