Syntheses and crystal structures of diorganotin(IV) bis(2‐pyridinethiolato‐N‐oxide) complexes

The complexes di‐n‐butyldi(2‐pyridinethiolato‐N‐oxide)tin(IV) (1), diphenyldi(2‐pyridinethiolato‐N‐oxide)tin(IV) ( 2 ) and dibenzyldi(2‐pyridinethiolato‐N‐oxide)tin(IV) ( 3 ) are synthesized and characterized by elemental analyses, IR, ¹H, ¹³C, ¹¹⁹Sn NMR spectroscopy, and their structures are determined by X‐ray crystallography. In complex 1 the coordination geometry at tin is a skew‐trapezoidal bipyramid, with cis‐S,S and cis‐O,O atoms occupying the trapezoidal plane and two n‐butyl groups occupying the apical positions, which also exhibits strong π–π stacking interactions. In complexes 2 and 3 the geometry at tin is distorted cis‐octahedral, with cis‐O,O and cis‐C,C atoms occupying the equatorial plane and trans‐S,S atoms occupying the apical positions. Their in vitro cytotoxicity against two human tumour cell lines, MCF‐7 and WiDr is reported. The ID₅₀ values found are comparable to those found for cis‐platin, but lower than for many other diorganotin compounds. Copyright © 2003 John Wiley & Sons, Ltd.