The crystal structure of the first synthetic copper(II) tellurite arsenate, CuII5(TeIVO3)2(AsVO4)2.

Crystals of the first synthetic copper tellurite arsenate, CuII5(TeIVO3)2(AsVO4)2 [systematic name pentacopper(II) bis-oxotellurate(IV) bis-oxoarsenate(V)], were grown by the chemical vapour transport method and structurally determined using single-crystal X-ray diffraction. CuII5(TeIVO3)2(AsVO4)2 possesses a novel structure type including a new topological arrangement of CuII and O atoms. CuII5(TeIVO3)2(AsVO4)2 is formed from a framework of two types of Jahn-Teller distorted [CuIIO6] octahedra (one of which is considerably elongated) and [CuIIO5] square pyramids, which are linked by edge-sharing to form chains and dimers and by corner-sharing to complete a three-dimensional framework. [AsVO4] tetrahedra and [TeIVO5] polyhedra bridge the edges of channels along the a-axis direction, with void space remaining for the TeIV stereoactive 5s2 lone pairs. A comparison is made between the crystal structure of CuII5(TeIVO3)2(AsVO4)2 and those of known compounds and minerals, in particular fumarolitic Cu minerals.