Cr6Te8(PEt3)6 and a Molecule-Based Synthesis of Cr3Te4

The molecular cluster compound Cr6Te8(PEt3)6 (1) is formed by the reaction of TePEt3 with either (Et3P)2Cr(allyl)2 or Cr(2,4-dimethylpentadienyl)2. This compound can be converted to the extended inorganic solid state compound Cr3Te4 by simple thermolysis. We have determined the structure of the title compound crystallographically (monoclinic; a = 13.076(5) Å, b = 21.194(7) Å, c = 23.694(7) Å, β = 105.21(5)°, V = 6276(10) Å3, Z = 4). The molecule is formed by a Cr6 octahedron, a Te8 cube, and a (PEt3)6 octahedron, all of which are concentric. We compare and contrast the structure and properties of the cluster with those of related solid-state compounds.