THE MOLYBDENOTUNGSTEN MONOPHOSPHATE MOWO3(PO4)(2) - AN ORIGINAL 3-DIMENSIONAL FRAMEWORK BUILT-UP OF MPO(8) CHAINS (M=MO, W)

A new molybdenotungsten monophosphate (MoxW2-x)O-3 (PO4)(2) has been s ynthesized for 0 less than or equal to x less than or equal to 1.25. T he crystal structure of the phase MoWO3(PO4)(2) has been determined. T his phase crystallizes in the P2(1)/m space group with a = 7.827(1) An gstrom, b = 12.538(1) Angstrom, c = 7.833(1) Angstrom, beta = 92.36(1) degrees. The structure can be described from the assemblage of two kin ds of [MPO(8)](infinity) chains running along b, with a cis and trans orientation of the PO4 tetrahedra. Another description which consists of the stacking of two different sorts of [M(2)P(2)O(15)](infinity) la yers along b is also presented that involves two sorts of bioctahedral units ''M(2)O(11)'' with the perovskite and HTB configurations, respe ctively. (C) 1997 Academic Press.