A V(III) PHOSPHATE BUILT-UP FROM BIOCTAHEDRAL V2O10 UNITS - AGV2(PO4)P2O7

Single crystals of a new V(III) phosphate AgV2(PO4)(P2O7) have been isolated, and its structure was determined from X-ray diffraction data. This phase crystallizes in the space group C2/c with a = 11.546(1) Angstrom, b = 8.548(1) Angstrom, c = 8.779(1) Angstrom, beta = 114.39(1)degrees, and Z = 4. The structure consists of monophosphate groups, diphosphate groups, and bioctahedral V2O10 units of two edge-sharing octahedra. The [V2P3O11](infinity) framework results from the stacking along c of eniantiomorphic [V2P3O16](infinity) layers. One [V2P3O16](infinity) layer can be described as built up either from [V2P2O14](infinity) chains of corner-sharing P2O7 and V2O10 groups connected through monophosphate groups or from [V2PO12](infinity) chains of corner-sharing V2O10 and PO4 units connected through diphosphate groups. This host lattice delimits cages where the silver ions are located with a distorted pentagonal bipyramidal coordination. This is to date the second V(III) phosphate involving V2O10 units linked through PO4 and P2O7 groups. (C) 1995 Academic Press, Inc.