Preparation of new zirconium phosphates by solvothermal reaction

Two types of new zirconium phosphates, [enH2]Zr(OH)(PO4)(HPO4) (en; ethylene diamine) and (NH4)5[Zr3(OH)9(PO4)2(HPO4)] were prepared under solvothermal condition using diethylene glycol as a solvent and their crystal structures were determined by using single crystal X-ray diffraction data. The former compound has the layer structure similar to that of c-Zr(PO4)(H2PO4) 2H2O, and protonated ethylene diamines were located in the interlayer space. At elevated temperatures, this compound decomposed by releasing protonated ethylene diamines and finally changed to ZrP2O7. The interlayer space was soft-chemically inactive unlike a-Zr(HPO4)2 H2O and c-Zr(PO4)(H2PO4) 2H2O. The later compound has the tunnel structure built up by corner-sharing ZrO6 octahedra and PO4 tetrahedra, and NH4 + ion was located in the tunnel