HYDROTHERMAL SYNTHESIS, STRUCTURE, AND SORPTION PROPERTIES OF CS(H3O)[MO2O2(PO4)2(HPO4)]

Yellow plates of Cs(H3O)[Mo2O2(PO4)2(HPO4)], (1), obtained in 60% yield from the reaction of Cs2MoO4, Mo, H3PO4, and H2O in a mole ratio of 5:1:30:57 for 24 hrs at 200°C, crystallize in the monoclinic space group P21 a with a = 9.166(4), b = 9.073(2), c = 15.808(3)Å, β = 96.85°, V = 1305(1)Å3, Z = 4, and R(Rw) = 0.087(0.085). The structure has MoOPO4-like layers held together with HPO4 groups and is structurally similar to (VO)2(SO4)2(H2SO4). The interlamellar space is compartmentalized into tunnels containing one-dimensional H-bonded strings of HPO4 groups alternating with strings of Cs+ and H3O+ cations. It is possible to remove water from the structure in a reversible manner as shown from water absorption isotherms. This same composition framework was prepared in a different crystal system and with a different cation by Clearfield and Peascoe (see J. Solid State Chem. 95(1), 83 (1991)). © 1991.