SYNTHESIS AND CHARACTERIZATION OF DI- AND TRIORGANOTIN(IV) DIETHYLDITHIOPHOSPHINATES. THE CRYSTAL AND MOLECULAR STRUCTURE OF BIS(DIETHYLDITHIOPHOSPHINATO)DIMETHYLTIN(IV), Me2Sn(S2PEt2)2

Article abstract of DOI:10.1016/0022-328X(87)80203-6

Bis(diethyldithiophosphinato)diorganotin(IV), R2Sn(S2PEt2)2, (R = Me, n-Bu, CH2Ph, Ph) and diethyldithiophosphinatotriorganotin(IV), R3SnS2PEt2 (R = Me, cyclo-C6H11, CH2Ph, Ph) were synthesized in nearly quantitative yield by reaction of organotin chlorides with sodium diethyldithiophosphinate.The compounds were characterized by infrared and 1H NMR spectra and, in part, by mass and 119mSn Moessbauer spectroscopy.The probable structure of the new compounds was inferred from the spectral data.The crystal and molecular structure of Me2Sn(S2PEt2)2 has been determined by X-ray diffraction.The compound is monoclinic, space group C'2/c, with a 20.814(11), b 6.243(3), c 16.092(8) Angstroem, β 105.42(8) deg, Z = 4, D_x 1.500 g cm^-3.The molecule exhibits a distorted tetrahedral environment around tin, with angles C-Sn-C 123.7(4) and S-Sn-S 80.6(2) deg.The bond distances within the dithiophosphinato ligand are P-S 1.961(2), P=S 2.054(2), P-C 1.825(10) and 1.787(8) Angstroem.The two tin-sulfur distances Sn-S 2.476(2) and Sn...S 3.336(2) Angstroem indicate the presence of two covalent bonds with additional non-bonded tin-sulfur interactions; the ligands can thus best be described as severely anisobidentate.