SYNTHESIS AND CRYSTAL-STRUCTURE OF IS(DIETHYLDITHIOCARBAMATO)IODOPHENYLTELLURIUM(IV), [PHTE(ET(2)NCS(2))(2)I]

The title compound, 1, was made by the reaction between [PhTe(Et(2)NCS (2))(3)] and I-2 in CH2Cl2. The yellow crystals are triclinic with a=1 0.124(3), b=13.762(5), c=17.592(6) Angstrom, alpha=83.61(2), beta=82.6 2(2), gamma=71.54(3)degrees, Z=4, space group P ($) over right arrow 1 and R=0.026 for 9113 unique, observed reflections. There are two crys tallographically independent molecules present, connected into pairs b y weak intermolecular Te ... S interactions of 3.598(1) and 3.832(1) A . These weak intermolecular Te ... S bonds are in a direction roughly tracts to the phenyl group. The structure of the molecules is essentia lly pentagonal bipyramidal with the phenyl group and a sulfur atom of a neighbour molecule being axial, and the sulfurs of the bidentate lig ands and iodine being in equatorial positions. Average Te-S, Te-I and Te-C bond lengths are 2.674, 3.126 and 2.153 Angstrom, respectively. T he roles of the secondary bonding and the lone pair of electrons on Te are discussed.