Manganese(iii) fluorophosphate frameworks

摘要

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_3F, PO_2(OH,F)_2 and Mn(O_(6-n),Fn) 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_3F, PO_2(OH,F)_2 and Mn(O,F)_6 octahedra.