Synthesis, characterization and structural studies of dithiocarbamate derivatives of 2,2,6,6-tetramethyl-1-oxa-4,4-diiodo-4-tellura-2,6-disilacyclohexane,O[Si(CH3)2CH2]2TeI(dtc)

Five new hetero-organotellurium (IV) dithiocarbamates O[Si(CH3)2CH2]2TeIS2CN(CH2CH2)2 (1), O[Si(CH3)2CH2]2TeIS2CN(CH2CH)2 (2), O[Si(CH3)2CH2]2TeIS2CN(CH2CH2)2O (3), O[Si(CH3)2CH2]2-TeIS2CN(CH2CH2)2S (4) and O[Si(CH3)2CH2]2TeIS2CN(CH2CH2)2CH2 (5) were prepared from the 2,2,6,6-tetramethyl-1-oxa-4,4-diiodo-4-tellura-2,6-disilacyclohexane and the corresponding dithiocarbamate (dtc) sodium salts in ethanol. The compounds were characterized by means of Elemental Analyses, FAB MS, IR, 1H, 13C, 125Te NMR spectroscopy. The crystal structures of 1, 3 and 4 were determined. Dithiocarbamate ligands display an anisobidentate chelating coordination mode on interacting with the tellurium center in all compounds. The Te(IV) immediate environment can be described as that of a sawhorse structure in which the lone pair is apparently stereochemically active and occupying an equatorial position in a distorted trigonal bipyramid. The two methylene groups occupy the other equatorial positions with a sulfur atom of the dithiocarbamate group and the iodine atom occupying the axial positions. The solid state structures of 3 and 4 exhibit important intermolecular interaction Te⋯S(2B). This interaction results in the formation of a dimer, which is better described as a distorted octahedron with an apparently inactive lone pair.