Synthesis, structure, ion-exchange and fluorescence of a novel two-dimensional niobium fluorophosphate with 4.8-net layer

A novel niobium fluorophosphate (NH4)2(Nb3P4O19F3)(H2en)2·H2O (1) has been synthesized by two-step hydrothermal method and characterized by elemental analyses, IR spectra, EDS analysis, PXRD, TG analysis and single-crystal X-ray diffraction. Compound 1 contains a novel two-dimensional 4.8-net layer constructed from the strict alternation of 4-connected NbO5F octahedra and 3-connected PO4 tetrahedra. 1 represents the first niobium fluorophosphate with the Nb/P ratio of 3/4. Furthermore, the ion-exchange and fluorescent properties of 1 have been studied.