PREPARATION, CHARACTERIZATION, AND STRUCTURE OF 2 LAYERED MOLYBDENUM(VI) PHOSPHATES - KMO(H2O)O2PO4 AND NH4MO(H2O)O2PO4

New layered Mo(VI) compounds, KMo(H2O)O2PO4 (I) and NH4Mo(H2O)O2PO4 (I I), were synthesized hydrothermally and their structures were determin ed from single-crystal X-ray analysis. Compounds (I) and (II) are isos tructural and crystallize in the monoclinic P2(1)/n space group with a = 12.353(3), b = 8.623(2), c = 5.841(1) Angstrom, beta = 102.78(1)deg rees, V = 606.8(2) Angstrom(3), Z = 4, and R = 0.027 (Rw = 0.030) for compound (I) and a = 12.435(3), b = 8.761(2), c = 6.015(1), beta = 103 .45(1)degrees, V = 637.3(2) Angstrom(3), Z = 4, and R = 0.040 (Rw = 0. 041) for compound (II). The structure consists of layers built up of e ight- and four-membered rings resulting from the alternation of corner -sharing [MoO6] octahedra and [PO4] tetrahedra. The layers stack along the ((1) over bar 01) direction by intercalating K and NH4 ions. (C) 1995 Academic Press, Inc.