Chalcogen-Rich Lanthanide Clusters: Compounds with Te^2-, (TeTe)^2-, TePh, TeTePh, (TeTeTe(Ph)TeTe)^5-, and [(TeTe)₄TePh]^9- Ligands; Single Source Precursors to Solid-State Lanthanide Tellurides

Lanthanide metals react with PhTeTePh and elemental Te in pyridine to give (py)yLn4(Te)(TeTe)2(TeTeTe(Ph)TeTe)(TexTePh) (Ln = Sm (y = 9; x = 0); Tb, Ho (y = 8, x = 0.1)), and (py)7Tm4(Te)[(TeTe)4TePh](Te0.6TePh) clusters. The Sm, Tb, and Ho compounds contain a square array of Ln(III) ions all connected to a central Te2- ligand. Two adjacent edges of the square are bridged by ditelluride ligands, with the Ln ion that is η2 bound to both of these TeTe ligands also coordinating to a terminal TePh ligand. The other two edges of the square are spanned by ditellurides that both coordinate a TePh ligand that has been displaced from the Ln ion by pyridine, to give the pentaanion (μ-η2-η2-Te2Te(Ph)Te2).- In the Tm compound, the displaced TePh interacts with all four TeTe units. The compounds are air-, light-, and temperature-sensitive. Upon thermolysis, they decompose to give solid-state TbTe2-x, HoTe, or TmTe, with elimination of Te and TePh2.