Crystal Structure of a Cerium(IV) Bis(phosphate) Derivative

Microcrystals of (NH4)2Ce(PO4)2·H2O were hydrothermally obtained from a CeO2−CO(NH2)2−H3PO4−H2O system (T = 180 °C). The structure [orthorhombic, Imma, a = 6.8940(9), b = 6.8860(9), c = 17.723(2) Å] consists of CeO8 distorted dodecahedra and PO4 tetrahedra joined together to form a three-dimensional framework with small four-sided and larger six-sided tunnels in quasi-equivalent directions. Ammonium ions and water molecules are situated inside the larger tunnels. Also, the thermal decomposition is discussed.