title: A new type of mixed anionic framework in microporous rubidium copper vanadyl(V) phosphate, Rb2Cu(VO2)2-(PO4)2.
abstract: In dirubidium copper bis[vanadyl(V)] bis(phosphate), Rb(2)Cu(VO(2))(2)(PO(4))(2), three different oxo complexes form an anionic framework. VO(5) polyhedra in a trigonal bipyramidal configuration and PO(4) tetrahedra share vertices to form eight-membered rings, which lie in layers perpendicular to the a axis of the monoclinic unit cell. Cu atoms at centres of symmetry have square-planar coordination and link these layers along [100] to form a three-dimensional anionic framework, viz. [Cu(VO(2))(2)(PO(4))(2)](infinity)(2-). Intersecting channels in the [100], [001] and [011] directions contain Rb(+) cations. Topological relations between this new structure type and the crystal structures of A(VO(2))(PO(4)) (A = Ba, Sr or Pb) and BaCrF(2)LiF(4 )are discussed.
authors.affiliation: Department of Geology, Moscow State Lomonosov University, Vorob'evy Gory, 119992 Moscow, Russian Federation. yakubol@geol.msu.ru
authors.forename: Olga V
authors.initials: OV
authors.lastname: Yakubovich
authors.forename: Ian M
authors.initials: IM
authors.lastname: Steele
authors.forename: Olga V
authors.initials: OV
authors.lastname: Dimitrova