Synthesis, spectroscopic characterization of O,O-alkylene dithiophosphates of tellurolane and 1-oxa-4-tellurane. Single crystal structures of C4H8Te[S2P(OCH2)2CMe-nPr]2 and C4H8OTe[S2P(OCH2)2CEt2]2

The synthesis of the four disubstituted organotellurium (IV) compounds, C4H8Te[S2P(OCH2)2CEt2]2 (1), C4H8Te[S2P(OCH2)2CMe-nPr]2 (2), C4H8OTe[S2P(OCH2)2CEt2]2 (3), C4H8OTe[S2P(OCH2)2CMe- nPr]2 (4), and one monosubstituted compound C4H8OTe(I)[S2P(OCH2)2CMe-nPr] (5), was achieved. All compounds were characterized by IR, EI, MS, and multinuclear NMR (1H, 13C, 31P, 125Te). In addition, the molecular structures of 2 and 3 were determined by X-ray analyses. Both structures are monomeric and the tellurium atom is bonded to two carbon atoms and to one sulfur atom of each one of the two anisobidentate dithiophosphate ligands. In 2, the geometry around Te(IV) is as that of a sawhorse structure in which the lone pair is apparently stereochemically active and occupying an equatorial position in a ψ-trigonal bipyramid. However, when the second sulfur atom of the dithiophosphate ligand is included in the coordination sphere, the environment about tellurium in the compound 2 can be described as bicapped ψ-trigonal bipyramid. Whereas in 3 it is a distorted octahedral structure in which the lone pair is stereochemically inactive.