A new three-dimensional sodium molybdenum(v) hydroxymonophosphate:: Na8(MO2O4OH)3(PO4)3(PO3OH)•12.25H2O

A new sodium molybdenum(v) hydroxymonophosphate, Na-8,(Mo-2,O-4,OH),(3)(PO4,),(3)(PO,3OH). 12.25 H,O-2 has been synthesized. It crystallizes in the monoclinic space group P2,(1)/c with a=13.024(4), b=25.936(4), c=13.276(3) Angstrom beta=111.72(2)degrees. Its structure involves Na[Mo,P-6(4),O-27,,(OH)(4)](2),, clusters similar to those encountered in several other molybdenum(v) hydroxyphosphates. Such clusters built up of two rings of six edge-sharing Mo octahedra interconnected through one NaO6, octahedron differ from those previously described by the fact that hydrogen is mainly connected to the Mo-O bond forming twelve Mo(O,5OH) octahedra, whereas among the eight tetrahedra one observes two P(O,3OH) tetrahedra and six PO4, tetrahedra. The originality of this structure deals with the fact that such clusters form with several sodium octahedra, Na(H2O),O-4(2), and Na(H2O),O-2(4),, a three-dimensional framework that delimits intersecting tunnels running along a, b and c. The coordination of other sodium cations and H2O molecules that can be considered as intercalated species is also discussed.