A SODIUM MO(V) MONOPHOSPHATE WITH A TUNNEL STRUCTURE - NA-3(MOO)(4)(PO4)(5)

A new molybdenum monophosphate Na-3(MoO)(4)(PO4)(5) has been synthesiz ed. It crystallizes in the space group C2/c with a = 16.789(1), b = 8. 500(1), c = 16.361(1) Angstrom, beta = 126.34(1)degrees. Its tridimens ional framework can be described by the stacking along b from [MO(4)P( 5)O(24)]infinity layers sharing the apices of their polyhedra and form ing cross-shaped tunnels running along that direction. The sodium ions are located on the walls of the tunnels, near large windows that allo w a communication between two adjacent tunnels. Molybdenum exhibits an octahedral coordination, characteristic of Mo(V), i.e., with an abnor mally short Mo-O bond corresponding to one free apex for each MoO6 oct ahedron. (C) 1995 Academic Press, Inc.