Example of unusual tetrahedral coordination of Cu(I) in oxides: Cu 3VO 4

Abstract

The crystal structure of the copper vanadate Cu 3VO 4, determined by X-ray powder diffraction, shows tetrahedral coordination of Cu(I) which is particularly unusual in oxides. Cu 3VO 4 presents a tetragonal unit-cell, isotypic to the famatinite Cu 3SbS 4, with the following parameters: a = 4.57531(9) Å; c = 8.9918(3) Å; space group I-42 m. Its structure can be described as a three dimensional framework of corner shared CuO 4 and VO 4 tetrahedra, distributed in an ordered way and forming pure copper-oxide layers [Cu 2O 4] ∞ alternating with mixed copper/vanadium oxide layers [CuVO 4] ∞. In the latter one observes a 1:1 ordering of the CuO 4 and VO 4 tetrahedra forming [CuVO 3] ∞ chains running along the [110] direction.