Copper(ii) fluorophosphates

Abstract

Eleven new copper fluorophosphate frameworks have been synthesised hydrothermally in a fluoride-rich medium, through the use of CuF(2) HPF(6) and monovalent metal fluorides as reactants. Products have been structurally characterised using single crystal X-ray diffraction. Reaction in fluoride-rich conditions produces chain, layer and three dimensional framework structures containing new and unusual structural features based on the linking of PO(3)F, PO(2)(OH,F)(2) and Cu(O,F)(n) polyhedra (n = 4-6). Analysis of these structures, in terms of the copper coordination environments and their linkage dimensionalities, shows that these features are dependent on fluoride-content of the reaction medium and, therefore, the level of fluoride ion incorporation into the product materials. Structures exhibiting inter-layer spaces and channels frequently have these lined by terminal fluoride anions of the PO(3)F, PO(2)(OH,F)(2) and Cu(O,F)(n) polyhedra.

Synthesis of Titanium Fluorophosphates and Fluorosulfates from Hexafluorotitanic Acid

“…Reactions undertaken in fluoride rich, low water content media produced by using hexafluorotitanic acid, H 2 TiF 6 as a reactant with phosphoric or sulfuric acids allow the formation of new network structures based on linked Ti(O,F) 6 octahedral and T(O,F) 4 (T = S, P) tetrahedral units.…”

“…[1][2][3][4][5]14,15] In the work reported herein we have employed hexafluorotitanic acid, H 2 TiF 6 , instead of titanium fluorides as a reactant to maintain high fluoride ion concentrations in the reaction medium.…”

“…[1][2][3][4] Such materials are of interest due to the functionality that arises from rigid and stable structures containing channels or pores, for example by making them highly suited to applications as battery cathode and anode materials. [5] Other applications of transition metal framework and layer structures based on linked polyhedral units include catalysis, molecular separations and, potentially, optoelectronic and magnetic material uses.…”

“…[15,16] In this work we have employed these large templating species in combination with hexafluorotitanic acid and oxo-fluoro-tetrahedral species (e.g. PO 4 3-, PO 3 F 2-, SO 3 F -, SO 4 2-) to generate four new phases that were structurally characterized using single-crystal X-ray diffraction. 2 crystallizes as small, ca.…”

“…40 ϫ 40 ϫ 10 μm colorless plates adopting a monoclinic unit cell with the space group P2/c. The structure consists of twodimensional layers of interconnected TiO 5 F octahedra with both PO 4 and PO 3 F tetrahedra as shown in Figure 1a and b. The fluoride ions of the TiO 5 F and PO 3 F polyhedra are di- rected into the interlayer spacing and form the coordination environment of the Cs + ion of eight fluoride ions at distances between 3.09 and 3.46 Å; the PO 4 tetrahedron forms the central unit of the layers and is linked through all vertices to titanium atoms.…”