Dimorphism of the Vanadium(V) Monophosphate PbVO2PO4: α-Layered and β-Tunnel Structures

A new type of mixed anionic framework in microporous rubidium copper vanadyl(V) phosphate, Rb2Cu(VO2)2(PO4)2

“…The novel crystal structure of rubidium copper vanadyl phosphate is closely related to the structures of A(VO 2 )(PO 4 ), with A = Ba, Sr or Pb (Kang et al, 1992;Borel et al, 2000), and BaCrF 2 LiF 4 (Babel, 1974), in having similar unit-cell parameters and the same space group, P2 1 /c (Table 3). In bc projections of the Ba(VO 2 )(PO 4 ) and Ba(CrF 2 )(LiF 4 ) crystal structures (Figs.…”

“…Six different structure types based on mixed anionic one-dimensional ribbons formed by VO 5 (or VO 6 ) and PO 4 polyhedra have been described: A(VO 2 )(HPO 4 ), with A = K, Rb, NH 4 or Tl (Amoros et al, 1988;Huan et al, 1991); the -modification of (NH 4 )(VO 2 )(HPO 4 ) (Amoros & Le Bail, 1992); A 2 (VO 2 )(PO 4 ), with A = K or Na (Korthuis et al, 1993a); K 3 (VO 2 ) 2 (PO 4 )(HPO 4 )(H 2 O) (Leclaire et al, 2002); Ba 2 (VO 2 )(PO 4 )(HPO 4 )(H 2 O) (Bircsak & Harrison, 1998a) and Cd(VO 2 )(PO 4 )(H 2 O) (Leclaire et al, 2000). Among the two-dimensional layered structures, four different types can be distinguished: K(VO 2 ) 2 (PO 4 ) (Berrah et al, 1999); A(VO 2 )-(PO 4 ), with A = Ba, Sr or Pb (Kang et al, 1992;Borel et al, 2000); Ag 2 (VO 2 )(PO 4 ) (Kang et al, 1993) and (CN 3 H 6 ) 2 -(VO 2 ) 3 (PO 4 )(HPO 4 ) (Bircsak & Harrison, 1998b Layers of VO 5 bipyramids and PO 4 tetrahedra linked by Cu atoms to form a three-dimensional anionic framework in the Rb 2 Cu(VO 2 ) 2 (PO 4 ) 2 crystal structure.…”

“…The three-dimensional microporous framework of CrF 6 octahedra and LiF 4 tetrahedra, with Ba atoms in channels, in the crystal structure of BaCrLiF 6 . the crystal structures of (NH 4 )(VO 2 ) 2 (PO 4 )(H 2 O) 3 (Wilde et al, 2000), Pb(VO 2 ) 2 (PO 4 ) (Borel et al, 2000) and Pb(VO 2 )-(PO 4 )(H 2 O) (Leclaire et al, 2001).…”

A Novel Phosphovanadate of Co(III) Hexammine: Co(NH3)6(V1.5P0.5)O6OH

“…At 1092 and 1047 cm\ we "nd the bands due to the asymmetric stretch (PO ) of the phosphate groups, followed by the corresponding symmetric mode (PO ) at lower wavenumbers (19}22). As already shown (23,24), the band wavenumbers corresponding to the (PO ) mode of the phosphate tetrahedra are low due to long P}O bonds generated by interactions between the oxygen atoms and the [Co(NH ) ]> cations. The (PO ) bending can be found at 537 cm\.…”

β-LiMoO2(AsO4)

“…La comparaison avec la forme du monophosphate PbVO 2 PO 4 (Borel et al, 2000) montre que la structure de ce dernier pre  sente le me à me type d'unite  s cycliques V 2 P 2 O 14 qui se connectent pour former des couches in®nies similaires a Á celles rencontre  es dans le compose  e  tudie Â, mais elles ne sont pas directement relie  es entre elles. La jonction des couches (V 2 P 2 O 14 ) I se fait par l'interme  diaire de deux types de te  trae Á dres VO 4 et PO 4 dans la forme -PbVO 2 PO 4 .…”