Synthesis of copper(II) and selenium(IV) oxochlorides by chemical transport reaction: crystal structure of Cu9O2(SeO3)4Cl6

The oxychloride of copper(II) and selenium(IV) are easily obtained by chemical transport reaction starting from CuO–SeO2–CuCl2 products. The molar ratio SeO2:CuCl2 controls the output of the reaction. Synthetic Cu9O2(SeO3)4Cl6 presents a lower symmetry than its natural chloromenite analog. It crystallizes in the monoclinic system, space group P21/n. The three-dimensional framework is formed by five different distorted coordination polyhedra of Cu(II) (CN4, 5, 7), [CuO2Cl2] rectangular, [CuO4] square planar, [CuO2Cl2] tetrahedron, [CuO4Cl] trigonal bipyramid, [CuO5Cl2] pentagonal bipyramid, and the one-sided [SeO3E] tetrahedron (E being the ns2 lone pair of Se(IV)). All these polyhedra share edges and corners to build the network.