(Pb2VO)-O-III (VO4)(O-2(7))(0.5), a novel lead vanadium III vanadate possessing trivalent vanadium rutile-like chains: Relationship with related compounds

摘要

The crystal structure of the new Pb2V3O8.5 has been determined and refined with final R-1 and wR(2) values 0.045 and 0.128, respectively, from 1063 independent single crystal reflections. It crystallizes with the P2/c space group, a = 7.687(2) Angstrom, b = 5.996(2) Angstrom, c = 17.337(4) Angstrom, and beta = 112.636(4)degrees. The structure consists of one-dimensional rutile-type chains of edge-sharing (VO6)-O-III octahedra parallel to the b axis. Bidentate (VO4)-O-V tetrahedra share corners with the chains to form one-dimensional columns. They are interconnected by divanadate (V2O7)-O-V to form infinite layers. In the presented work, the Pb2V3O8.5 crystal structure is compared to several closely related materials including Ba2V3O9 and the mineral Vauquelinite Pb2CuCrO4PO4OH. Special attention is given to the existence along the rutile chains of V-V pairs due to strong V-O bonds with O-2 bridging edges. (C) 2002 Elsevier science. [References: 48]