Trialkylphosphine-Stabilized Copper−Phenyltellurolate Complexes: From Small Molecules to Nanoclusters via Condensation Reactions

Abstract

Reactions of CuCl with Te(Ph)SiMe3 and solublizing trialkylphosphine ligands afford a series of polynuclear copper−phenyltellurolate complexes that has been structurally characterized. The formation of the complexes is found to be highly dependent on the ancillary phosphine ligand used. The synthesis and structures of [Cu2(μ-TePh)2(PMe3)4] 1, [Cu4(μ3-TePh)4(PPri3)3] 2, [Cu5(μ-TePh)3(μ3-TePh)3(PEt3)3][PEt3Ph] 3, and [Cu12Te3(μ3-TePh)6(PEt3)6] 4 are described. The telluride (Te2-) ligands in 4 arise from the generation of TePh2 in the reaction mixtures. The subsequent co-condensation of clusters 3 and 4 leads to the generation of the nanometer sized complex [Cu29Te9(μ3-TePh)10(μ4-TePh)2(PEt3)8][PEt3Ph] 5 in good yield, in addition to small amounts of [Cu39(μ3-TePh)10(μ4-TePh)Te16(PEt3)13] 6. These complexes are formed via the photo elimination of TePh2. The cyclic voltammogram of 5 in THF solution exhibits two oxidation waves, assigned to the oxidation of the Cu(I) centers.