THE CRYSTAL-STRUCTURE OF K-2[CU3ZNF(PO4)(3)], A NEW MIXED ZINC COPPERPHOSPHATE

The title compound has been prepared by hydrothermal synthesis and its crystal structure was determined by single crystal X-ray diffraction: space group P2(1)/m, a = 4.8890(2), b = 14.3857(5), c = 7.9017(3) Ang strom, beta = 90.134(4)degrees, wR(2) = 0.123, R = 0.045. Cu2+ has two different coordination polyhedra: an elongated square pyramidal [CuFO 4] and square planar [CuO4] coordination in a 2:1 ratio. Edge-sharing double-pyramids and [CuO4] squares form zig-zag chains interconnected by [ZnO4] and [PO4] tetrahedra to form an open anionic framework struc ture whose channels are occupied by the K+ ions.