Synthesis, structure, spectroscopic properties and biological activity of mixed diorganotin (IV) complexes containing pyridine-2-carbaldehyde thiosemicarbazonato and diphenyldithiophosphinato ligands

Reaction of the title ligands (HPyTSC and HS(S)PPh2, respectively) with R2S nO (R = Me, Et, Bu) in ethanol (EtOH) afforded the complexes [SnMe2(PyTSC) (S2PPh2) . EtOH (1) and [SnR2(PyTSC) (S2PPh2) ] (R = Et (2), Bu (3)). The s tructures of 1 and 2 were determined by single-crystal X-ray diffractometry . In both these complexes the tin atom is coordinated to an N,N,S-dentate t hiosemicarbazonate ligand, an anisobidentate dithiophosphinato ligand and t he two R groups. The coordination polyhedrons can be described as distorted pentagonal bipyramids. A comparative study of the IR spectra of 1, 2 and 3 indicates that the butyl complex has a similar structure. Multinuclear (H- 1, C-13, P-31 and Sn-119) NMR data suggest that the structures of 1 and 2 p robably remain in CDCl3 (or DMSO-d(6)) solution but compound 3 partially de composes in these media. Preliminary results on the effects of the complexe s on the proliferation and differentiation of FLC, GEM, U937, K562 and TOM- 1 leukaemia cells, and on the clonogenic activity of K562 cells are also de scribed. (C) 1999 Elsevier Science Inc. All rights reserved.