Synthesis and spectroscopic characterization of new mixed ligand organotellurium(IV) compounds employing dithiocarbamates and imidotetraphenyldithiodiphosphinates. Crystal structure of [C4H8Te(S2CNEt2){(SPPh2)(2)N}], [C4H8Te(CNC5H10){(SPPh2)(2)N}] and [C4H8Te(S2CNC4H8S){(SPPh2)(2)N}]

The synthesis of new mixed ligand organotellurium(IV) compounds, [C4H8Te(S2 CNEt2){(SPPh2)(2)N}] (1), [C4H8Te-(S2CNC5H10){(SPPh2)(2)N}] (2), [C4H8Te(S2 CNC4H8O){(SPPh2)(2)N}] (3) and [C(4)HsTe(S2CNC4H8S){(SPPh2)(2)N}] (4), was achieved. They were characterized by FAB(+) mass spectrometry, IR, H-1-, C- 13-, P-31- and Te-125-NMR spectroscopy. The crystal structures of 1, 2 and 4 were determined by X-ray diffraction. The solid state structures show tha t the coordination geometry can be described as the sawhorse structure typi cal for Te(IV) in which the lone pair is regarded as stereochemically activ e and occupying an equatorial position in a distorted trigonal bipyramid. B oth types of ligands exhibit an anisobidentate chelating coordination mode on interaction with the tellurium center. If the aniso-bonded donor atoms a re included in the coordination sphere, the coordination number increases t o seven and the environment at Te can be described as the 1:2:2:2 structure . No intermolecular interaction was observed. (C) 2001 Published by Elsevie r Science B.V.