A new chain structure: catena-poly[4,4 '-(ethane-1,2-diyl)dipyridinium bis[[aquadifluoridooxidovanadate]-mu-fluorido]]

The title compound, {(C12H12N2)[V2F6O2(H2O)(2)]}(n), features a novel extended-chain moiety, [VOF2F2/2(H2O)](n), comprising trans vertex-connected VOF4(H2O) octahedra. The octahedra themselves show the characteristic distortion due to the off-centring of the V4+ ion, such that a short terminal V=O bond and an elongated trans V-OH2 bond are present. Hydrogen bonding from the water molecules to terminal F atoms in adjacent chains generates associated chain dimers, which are loosely linked into sheets via additional hydrogen bonding involving the organic moieties. Structural relationships with previously described vanadium oxyfluoride species are briefly discussed.