Heptasodium tetraaluminium tetrakis(diphosphate) orthophosphate, Na₇Al₄(P₂O₇)₄(PO₄)

Abstract

Key indicators: single-crystal X-ray study; T = 296 K; mean (P-O) = 0.002 Å; R factor = 0.017; wR factor = 0.047; data-to-parameter ratio = 11.4.The asymmetric unit of title compound contains three Na + , one Al 3+, three P 5+ and eight O 2À atoms, with one Na + atom lying on a twofold rotation axis and one Na + and one P 5+ atom on fourfold rotoinversion axes. The fundamental building units of the title structure are isolated PO 4 tetrahedra, AlO 6 octahedra and P 2 O 7 groups, which are further interlocked by corner-sharing O atoms, forming a three-dimensional framework structure. The Na + atoms are located within the cavities of the framework, showing coordination numbers of 4, 6 and 7. Related literature ExperimentalCrystal data

Structure Determination and Luminescent Property Studies of the Single Crystal Na3Sm(BO3)2

“…The coordination environment Na3 atom is surrounded by five O atoms into a Na3O 5 polyhedron with three shorter Na3−O bond distances (2.301(3) Å, 2.350(3) Å, and 2.375(3) Å) and two longer Na3−O bond distances (2.893(4) Å and 3.071(3) Å), which can be considered as secondary coordination bonds to complete the extended coordination spheres of the large Na + ion. The coordination mode of Na3O 5 shows a big difference from those of Na1O 7 and Na2O 6 , and is an uncommon coordination geometry compared with other reported Na(I) oxide compounds [19]. Although the ionic radii of Sm 3+ (0.964 Å) is comparable with that of Na + (0.950 Å), it adopts a Sm1O 8 coordination mode with a Sm1−O bond length of 2.338(3)-2.518(2) Å.…”

“…The coordination mode of Na3O5 shows a big difference from those of Na1O7 and Na2O6, and is an uncommon coordination geometry compared with other reported Na(I) oxide compounds [19]. Although the ionic radii of Sm 3+ (0.964 Å) is comparable with that of Na + (0.950 Å), it adopts a Sm1O8 coordination mode with a Sm1−O bond length of 2.338(3)-2.518(2) Å.…”

Ionic behavior, Na+ mobility and infrared spectroscopy in Na7Cr4(P2O7)4PO4 material

“…The Na7M4(P2O7)4PO4 with (M = Fe, Al, Cr) compound family containing mono-and pyrophosphate groups was discovered by De la Rochère et al [19]. In this series, the Na7In4(P2O7)4PO4 and Na7Al4(P2O7)4PO4 compounds were synthesized and investigated by Stus [20] et al and Zhao [21] respectively. Using lithium, some other compounds like Li9V3(P2O7)3(PO4)2 [16,17] and Li9M3(P2O7)3(PO4)2 (M = Al, Ga, Cr, Fe) [18] were synthesized and structurally investigated.…”