The Flexibility of P2O7 Dimers in Soft Structures: M2CdP2O7 (M = Rb, Cs)

Abstract

The new compounds Rb2CdP2O7 (I) and Cs2CdP2O7 (II) are prepared by calcination of stoichiometric mixtures of Rb2CO3 (Cs2CO3), CdO, and NH4H2PO4 (650 °C, 72 h).

A New Cadmium‐Based Pb2Cd3(PO4)2(P2O7) with Two Types of Isolated P–O Groups

“…Therefore, the results of the IR spectrum confirm the presence of diphosphate units and PO 4 units. The results coincide with previous reports , …”

Cadmium phosphates with two types of fundamental building units and a wide ultraviolet transparency window

“…The UV cut-off edges of KCd 6 P 7 O 24 and KCd 3 P 3 O 11 are less than 200 nm. We can find that the UV cut-off edges of KCd 6 P 7 O 24 and KCd 3 P 3 O 11 are shorter than those of other Cd phosphates, such as Rb 2 CdP 2 O 7 34 (210 nm), Cd 4 BiO(BO 3 ) 3 35 (390 nm), and Cs 2 CdP 2 O 7 34 (300 nm). The wide UV transparency window of the title compound suggests that they can serve as optical materials for UV application.…”

Phase Stability of Lead Phosphate Apatite Pb10–xCux(PO4)6O, Pb10–xCux(PO4)6(OH)2 (x = 0, 1), and Pb8Cu2(PO4)6

“…These tetrahedra can be flexibly arranged in various ways, facilitating the assembly of diverse P x O y groups, resulting in the formation of intricate motifs such as rings, chains, 15 and isolated dimers. 16 Moreover, lead phosphates can adopt multiple different stoichiometries and polymorphs (e.g., P 2 Pb 3 O 8 is reported to adopt C2/c, R3̅ m, and C2/m space groups, and their energies are within 50 meV/atom), which often exhibit near degeneracies and metastabilities, resulting in a complex phase space. Recent density functional theory (DFT) studies have examined some of the properties and electronic structures of various family members of lead phosphates, including LK-99.…”

“…LK-99’s parent structure, lead phosphate apatite, contains a mixed polyanionic framework, where phosphorus atoms are 4-fold coordinated with oxygen to form (PO 4 ) x tetrahedra, constituting the building blocks of lead phosphate structures. These tetrahedra can be flexibly arranged in various ways, facilitating the assembly of diverse P x O y groups, resulting in the formation of intricate motifs such as rings, chains, and isolated dimers . Moreover, lead phosphates can adopt multiple different stoichiometries and polymorphs (e.g., P 2 Pb 3 O 8 is reported to adopt C 2/ c , R 3̅ m , and C 2/ m space groups, and their energies are within 50 meV/atom), which often exhibit near degeneracies and metastabilities, resulting in a complex phase space.…”