Synthesis, crystal structure and characterization of the barium zinc tellurate disilicate: Ba3Zn6[TeO6][Si2O7](2)

The new barium zinc(II) tellurate disilicate Ba3Zn6[TeO6][Si2O7](2) was synthesized by the high temperature solid state reaction of BaCO3, ZnO, and SiO2 with TeO3 center dot H2O in a molar ratio of 3:6:4:1 in an evacuated silica tube at 820 degrees C. Its structure was established by single-crystal X-ray diffraction. Ba3Zn6[TeO6][Si2O7](2) crystallizes in the monoclinic system, space group C21m (no. 12), with cell parameters of a = 15.975(5), b = 11.505(4), c = 5.142(2) angstrom, beta = 107.437(5)degrees, V = 901.7(5) angstrom(3), and Z = 2. The structure of Ba3Zn6[TeO6][Si2O7]2 is composed of two types of zinc oxide polyhedra ([ZnO4] tetrahedra and [ZnO6] octahedra), [TeO6] octahedra, disilicate group [Si2O7], [BaO6] and [BaO7] polyhedra. It can be described as a three-dimensional anionic network of {Zn-6[TeO6][Si2O7](2)}(6-), which is built from one-dimensional chains of [Zn6TeO18](18-) anion interconnected by disilicate [Si2O7](6-) groups with the barium cations located at the six-membered apertures of the above-mentioned anionic network.