The Mixed Valent Molybdenum Monophosphate RbMo2P2O10 · (1 - x)H2O: An Intersecting Tunnel Structure Isotypic with Leucophosphite

✍ Scribed by A. Leclaire; M.M. Borel; A. Grandin; B. Raveau

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 317 KB
• Volume: 108
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1994.1027

✦ Synopsis

A new molybdenum monophosphate (\mathrm{RbMo}{2} \mathrm{P}{2} \mathrm{O}{10} \cdot(1-x) \mathrm{H}{2} \mathrm{O}), with the mixed valence (\operatorname{Mo}(\mathrm{V})-\operatorname{Mo}(\mathrm{IV})) has been synthesized by conventional techniques. Its structure has been solved from single crystal X-ray diffraction in the space group (P 2_{1} / c) with (a=) 9.789(1) (\AA, b=9.752(1) \AA, c=12.347(1) \AA, \beta=) 128.81(1) ({ }^{\circ}). This compound, isotypic with (\mathrm{NH}{4} \mathrm{Mo}{2} \mathrm{P}{2} \mathrm{O}{10} \cdot \mathrm{H}{2} \mathrm{O}) described by King et al., J. Solid State Chem. 92, 1 (1991), exhibits the leucophosphite structure. A new description of this open framework, involving (\left[\mathrm{MoPO}{8}\right]{\infty}) chains and (\mathrm{Mo}{2} \mathrm{P}{2} \mathrm{O}{10}) units built up of two edge-sharing (\mathrm{MoO}{6}) octahedra bridged by two (\mathrm{PO}{4}) tetrahedra, is proposed. The (\mathrm{Rb}) phosphate differs from the (\mathrm{NH}_{4}) phase by the distribution of (\mathrm{Rb}^{+})cations which partially occupy three kinds of sites, whereas one observes only one sort of site, fully occupied, in the ammonium phase. The possibility of a large stoichiometry deviation in the interpolated cation is considered. (1994 Academic Press, Inc.