Synthesis, characterization and cytotoxic activity of complexes of diorganotin(IV) dihalides with mepirizole

Reaction of mepirizole (M) with diorganotin(IV) dihalides yielded compounds of type [SnR 2 X 2 (M)] (R, X = Et, Cl; Et, Br; Bu, Cl; Bu, Br; Ph, Cl). The structure of dichlorodiphenyl (mepirizole)tin(IV) was determined by X-ray diffractometry. The crystal consists of discrete [SnPh 2 Cl 2 (M)] units in which an N,N'-bidentate mepirizole, the trans phenyl rings and the cis chlorine atoms define a pseudo-octahedral coordination polyhedron around the tin atom. Mossbauer and vibrational spectroscopic data suggest similar structures for the other compounds prepared. The 1 H NMR spectra show that the mepirizole ligand is largely dissociated in CDCl 3 . The most active compounds against the human carcinoma cell line KB were the butyl derivatives.