An ionothermally prepared S = 1/2 vanadium oxyfluoride kagome lattice.

Frustrated magnetic lattices offer the possibility of many exotic ground states that are of great fundamental importance. Of particular significance is the hunt for frustrated spin-1/2 networks as candidates for quantum spin liquids, which would have exciting and unusual magnetic properties at low temperatures. The few reported candidate materials have all been based on d(9) ions.

Protecting group and switchable pore-discriminating adsorption properties of a hydrophilic-hydrophobic metal-organic framework.

Formed by linking metals or metal clusters through organic linkers, metal-organic frameworks are a class of solids with structural and chemical properties that mark them out as candidates for many emerging gas storage, separation, catalysis and biomedical applications. Important features of these materials include their high porosity and their flexibility in response to chemical or physical stimuli. Here, a copper-based metal-organic framework has been prepared in which the starting linker (benzene-1,3,5-tricarboxylic acid) undergoes selective monoesterification during synthesis to produce a solid with two different channel systems, lined by hydrophilic and hydrophobic surfaces, respectively.

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

The title compound, {(C(12)H(12)N(2))[V(2)F(6)O(2)(H(2)O)(2)]}(n), features a novel extended-chain moiety, [VOF(2)F(2/2)(H(2)O)](n), comprising trans vertex-connected VOF(4)(H(2)O) octahedra. The octahedra themselves show the characteristic distortion due to the off-centering of the V(4+) ion, such that a short terminal V=O bond and an elongated trans V-OH(2) 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.

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.

Novel vanadium(IV) oxyfluorides with 'spin-ladder'-like structures, and their relationship to (VO)2P2O7.

Three novel vanadium(IV) oxyfluorides have been prepared by hydrothermal synthesis. All three materials feature 'ladder'-like chains of edge- and corner-sharing V(O/F) octahedra, topologically similar to those in (VO)2P2O7. CsVOF3 and RbVOF3 are isostructural, whereas in (bpeH2)1/2[VOF3] (bpe = trans-1,2-bis(4-pyridyl)-ethylene) inclusion of the organic structure-directing agent affects both the conformation of the ladders and their packing within the unit cell.