A molybdenotungsten monophosphate with an opened structure K6.6Mo2.36W3.64O15(PO4)4

Abstract A new “MoW” monophosphate K 6.6 Mo 2.36 W 3.64 O 15 (PO 4 ) 4 has been synthesized. This complex opened structure crystallizes in the R 3 group with a = 17.545(2) A and c = 15.714(2) A. The [M 6 P 4 O 31 ] ∞ framework can be described from M 3 P 3 O 19 and M 6 P 6 O 48 units. The first unit consists of one PO 4 tetrahedron sharing its apices with three MO 6 octahedra, whereas the second one forms hexagonal rings in which one MO 6 octahedron alternates with one PO 4 tetrahedron. Another interesting feature of this framework deals with the existence of spiral-like octahedral [MO 5 ] ∞ chains running along[formula], so that the structure can also be described as an assemblage of these chains through PO 4 tetrahedra. This framework offers large cages that communicate with each other, so that five different sites are available for potassium.