Hydrofluorothermal methods are shown to offer a facile route to a very large family of mid-late first row, transition metal fluorophosphates with 50 new compounds identified to date for manganese(III), iron(III), cobalt(II), and copper(II). Reactions of a transition metal fluoride with a phosphate source in a very low-water, high-fluoride content system and in the presence of framework charge balancing metal cations or template molecular cations, lead to materials with structures formed from linked M(O,F)(n) and P(O,F)(n) polyhedra. The structures of these materials, which contain a variety of 1, 2, and 3-dimensional motifs with a level of framework termination dependent upon their fluoride content, show numerous useful characteristics for functionality and applications. The new and unusual features of these fluorophosphate materials include interlayer spaces or channels lined with fluoride ions, metal polyhedra, M(O,F)(n), linked through vertex, edge, or face-sharing, and μ(2), μ(3), and μ(4) bridging fluoride ions. Preliminary characterization of the properties of some of these metal fluorophosphates is reported, including reductive lithium ion insertion, of interest for Li-ion battery positive electrodes, ion exchange reactions, the formation of nanoporous material derivatives through template destruction, and magnetic susceptibility behaviors.

The effect of various compositional substitutions on the colour of long-lived F-centres in the sodalite structure has been investigated by the synthesis and characterisation of several phases of the general composition A 8 [M 0 M 00 O 4 ] 6 [X,S] 2 . The visible-region absorption spectrum of the excited state, formed by 256 nm irradiation of the as-synthesised materials, shows a broad absorption whose position correlates with the dimensions of the sodalite cage occupied by the excited electron.

Nine new manganese(III) fluorophosphates have been synthesised hydrothermally in a fluoride-rich medium, through the use of MnF(3), 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 Mn(O(6-n),F(n)) octahedra, with n averaging 2.8 over the family of compounds. The Mn(III), d(4), oxidation state is stabilised under these reaction conditions and products frequently show Jahn-Teller distorted Mn(O,F)(6) units with axially elongated Mn-O or, less commonly, Mn-F distances. 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 Mn(O,F)(6) octahedra.

Nine new cobalt fluorophosphates frameworks have been synthesised hydrothermally in a fluoride-rich medium, through the use of CoF(3) and HPF(6) as reactants in combination with Group I/II metal hydroxides and organic cations as templating species. 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 Co(O,F)(n) polyhedra (n = 5-6) including μ(2), μ(3) and μ(4) bridging fluoride. 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 Co(O,F)(n) polyhedra.

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.