Diorganotin dihalide complexes of N-bidentate ligands: Crystal structures of diethyldibromo- and dibutyldichloro[bis(1-methyl-2-imidazolylthio)methane]tin(IV)

The compounds [SnR2X2(bmimt)] (R = Me, Et, Bu; X = CI, Br; bmimt = bis(1-me thyl-2-imidazolylthio)methane) have been prepared and characterized by cond uctivity measurements and by IR, Raman, mass, Mossbauer and H-1 NMR spectro scopy. The structures of the diethyldibromo- and dibutyldichlorotin(IV) der ivatives were determined by X-ray crystallography, The crystals consist of two slightly different types of discrete [SnR2X2(bmimt)] unit with the meta l atom octahedrally coordinated to the two halogen atoms, two alkyl carbons and the two nonmethylated nitrogen atoms of the ligand, This coordination mode, which the spectroscopic data suggest is also present in all the other complexes studied, results in the formation of an eight-membered CS2C2N2Sn ring. The Sn- N distances in [SnEt2Br2(bmimt)] (2.53 and 2.42 Angstrom) an d [SnBu2Cl2(bmimt)] (2.52 and 2.47 Angstrom), suggest that these compounds may have antitumour activity. Copyright (C) 1999 John Wiley & Sons, Ltd.