A MIXED-VALENT MOLYBDENUM MONOPHOSPHATE WITH A LAYER STRUCTURE - CSMO2O3(PO4)(2)

A new mixed valent molybdenum monophosphate Cs Mo2O3(PO4)(2) has been synthesized in the form of single crystals. It crystallizes in the spa ce group P2(1)/c with a = 10.047(2) Angstrom, b = 8.655(1) Angstrom, c = 11.597(2) Angstrom, beta = 104.27(1)degrees. This phase exhibits an original layered structure, in which the [Mo2P2O11](infinity) layers consist of [MoPO8](infinity) chains connected with [MoPO7](infinity) c hains. In the [MoPo8](infinity) chains, one MoO6 octahedron alternates with one PO4 tetrahedron, whereas in the [MoPO7](infinity) chains one MoO5 trigonal bipyramid alternates with one PO4 tetrahedron. The geom etry of the MoO6 octahedra and MoO5 bipyramids is in agreement with th eir occupancy by Mo(V) and Mo(VI), respectively. The Cs+ cations inter leaved between these layers exhibit a monocapped distorted cubic coord ination. (C) 1995 Academic Press, Inc.