Hydrothermal chemistry of oligomeric vanadium oxyfluorides.

Nine new vanadium oxyfluorides, containing ten different oligomeric vanadium (oxy)fluoride anions have been prepared by solvothermal synthesis in water-ethylene glycol and using organic cations as co-crystallising agents. Crystal structures are reported for each. Amongst the ten structure types, five represent previously unobserved moieties, including one monomeric unit (cis-[VOF4(H2O)]2-), two dimers ([V2O2F6(H2O)2]2- and [V2O2F8]4-) and two tetramers (both isomers of composition [V4O4F14]6-).

Hydrothermal vanadium fluoride chemistry: four new V3+ chain structures.

An exploratory study of the hydrothermal chemistry of vanadium in HF solutions has resulted in the preparation of four new vanadium (III) fluorides with chainlike structural motifs. [NH4]2[VF5] (1) and [C2N2H10][VF5] (2) feature infinite chains of trans corner-sharing VF4F2/2 octahedra, [C4N2H6][VF5].H2O (3) has cis corner-sharing [VF4F2/2]infinity chains, and [C10N2H8][VF3] (4) has trans corner-sharing [VF2F2/2]infinity chains bridged into sheets by the 4,4'-bipy linker.

Ammonium scandium tetrafluoride.

The title compound, NH4ScF4, is an addition to the AMF4 family of layered perovskite-like structures. The structure consists of a two-dimensional array of corner-sharing ScF6 octahedra, which produces anionic sheets of stoichiometry [ScF4]- stacked along the c axis. The layers are separated by charge-balancing ammonium cations, which hydrogen bond to the apical F atoms of adjacent layers.

A second polymorph of [H3N(CH2)3NH3][V4O10].

The title compound, propane-1,3-diammonium tetravanadate, (C3H12N2)[V4O10], represents a second polymorph of composition beta-[H3N(CH2)3NH3][V4O(10)]. It differs from the alpha polymorph [Riou & Ferey (1995). J.

Ethylenediaminium niobium oxyfluoride.

The title compound, bis(ethylenediaminium) mu-oxo-bis[tetrafluorooxoniobium(V)], (C2H10N2)2[Nb2O3F8], is a novel organically templated niobium oxyfluoride. It consists of isolated [Nb2O3F8]4- octahedral dimers charge balanced by ethylenediaminium cations, two of which lie about inversion centres. Two NbO2F4 octahedra are fused through a common O atom to form the dimers.

A novel scandium fluoride, [C2N2H10]0.5[ScF4], with an unprecedented tungsten bronze-related layer structure.

[C(2)N(2)H(10)](0.5)[ScF(4)] exhibits isolated anionic layers of corner-linked ScF(6) octahedra enclosing 3-, 4-, 5- and 6-membered rings, with features reminiscent of both hexagonal and tetragonal tungsten bronze-type structures.