ZINC(II) ARENE TELLUROLATO COMPLEXES AS PRECURSORS TO ZINC TELLURIDE - THE CRYSTAL AND MOLECULAR-STRUCTURE OF [ZN(TEC(6)H(2)ME(3)-2,4,6)(2)(PYRIDINE)(2)]

The zinc tellurolato complex [Zn(TeC(6)H(2)Me(3)-2,4,6)(2)](n) (1) was obtained by protolysis of Zn[N(SiMe(3))(2)](2) with mesitylene tellurol, 2,4,6-Me(3)C(6)H(2)TeH, in light petroleum. The complex formed a coordination polymer soluble only in strongly coordinating solvents. Reaction with one equivalent of PMe(3) afforded [Zn(TeC(6)H(2)Me(3))(2)(PMe(3))] (2), while an excess of Lewis bases L gave four-coordinate adducts [Zn(TeC(6)H(2)Me(3))(2)L(2)] [L = PMe(3) (3), N-methylimidazole (5), pyridine (6), L(2) = Me(2)PC(2)H(4)PMe(2) (4)]. The adducts are more soluble than 1 but lose L on heating. The crystal structure of 6 has been determined by X-ray diffraction and confirmed the monomeric nature of the complex. Heating the complexes either without a solvent or in paraffin oil to 270-320 degrees C led to the formation of cubic ZnTe. Prolonged exposure to temperatures of 350 degrees C in vacuo led to the slow decomposition of ZnTe into the elements. The thermolysis of 1 in refluxing 4-ethylpyridine proceeded more slowly giving nano-scale particles of ZnTe, accompanied by the formation of crystalline tellurium.