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

Abstract

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.

Crystallization Pathways of Cerium(IV) Phosphates Under Hydrothermal Conditions: A Search for New Phases with a Tunnel Structure

“…Thermal analysis data for (NH 4 ) 2 Ce(PO 4 ) 2 (H 2 O), Ce(PO 4 )(HPO 4 ) 0.5 (H 2 O) 0.5 and NH 4 Ce 2 (PO 4 ) 3 are presented in Figure S4 a,b and Figure , respectively. The thermal behavior of (NH 4 ) 2 Ce(PO 4 ) 2 (H 2 O) and Ce(PO 4 )(HPO 4 ) 0.5 (H 2 O) 0.5 phases is in agreement with previously reported data , …”

“…S1–S3). In particular, the use of NH 4 OH in concentrations above 2 m resulted in the formation of (NH 4 ) 2 Ce(PO 4 ) 2 (H 2 O) phase, as described by Salvado et al In turn, the use of intermediate concentrations of NH 4 OH (0.1–2 m ) led to the crystallization of a phase which is absent in the ICDD PDF database.…”

“…Salvado et al synthesized (NH 4 ) 2 Ce(PO 4 ) 2 · H 2 O by a similar hydrothermal method using CeO 2 , CO(NH 2 ) 2 and H 3 PO 4 as starting materials, and revised the structural data presented by Xu et al According to Salvado et al, the structure of this compound comprises eight‐coordinated cerium atoms interconnected with phosphate groups and contains tunnels of various sizes with ammonium ions and water molecules.…”

Zirconium Phosphate/Fibrous Cerium Phosphate Nanocomposite Membrane Self Supported Benzimidazole, Its Co-Aniline, Co-Pyrrole and Co-Indole Polymerization Agent

“…Cerium phosphates have been studied for a long time as ion exchangers, their structures remains unknown until recently [53][54][55]. The reason is that, the composition, the structure and the degree of crystallinity of their precipitates results from reaction of solutions containing a Ce IV salt is mixed with a solution of phosphoric acid of [(PO 4 )/Ce(iv) ratio], strongly dependent on the experimental conditions such as rate and order of mixing of the solutions, stirring, temperature and digestion time, this also implemented on fibrous cerium phosphate [50,56].…”

Eco-Efficient Synthesis of LiFePO[sub 4] with Different Morphologies for Li-Ion Batteries

“…To remedy these issues, we searched for different synthetic approaches and have been inspired by recent studies aiming toward the low-temperature synthesis of various inorganic compounds, either in bulk or nanocrystalline forms, such as ammonium-thorium phosphates, 12 16 via the use of a basic medium created by the temperature-driven decomposition of urea. Herein we implemented the aforementioned approach to the synthesis of tailor-made LiFePO 4 powders via a solvothermal process in either aqueous or nonaqueous solvents.…”