Hydrothermal synthesis and characterization of a novel 3D open framework structure of mixed valence ethylenediamine–vanadium phosphate: [C2H10N2][(HVIVO3)(HVVO2) (PO4)]

A new three-dimensional open framework structure of mixed valence ethylenediamine–vanadium phosphate [C2H10N2][(HVIVO3)(HVVO2)(PO4)] (1), has been synthesized under mild hydrothermal conditions and characterized by elemental analyses, IR, fluorescent spectrum, TG-DTA and single crystal X-ray diffraction. Compound 1 exhibits a novel three-dimensional (3D) vanadium phosphate anion framework composed of vanadium, phosphate, and oxygen atoms through covalent bonds, with the diprotonated ethylenediamine [NH3CH2CH2NH3]2+ cations residing in the channels along c-axis. The organic diprotonated ethylenediamine cations interact with the O atoms in the inorganic network through hydrogen bonds. The electrochemical behavior of 1 has also been studied in detail by cyclic voltammograms, which is very important for practical applications in electrode modification. Furthermore, the strong photoluminescence property of compound 1 is also measured at room temperature.