Sn₆[P₁₂N₂₄] – A Sodalite‐Type Nitridophosphate

Abstract

Sn 6 [P 12 N 24 ] was synthesized from Sn and HPN 2 at 820°C in an evacuated silica glass ampoule. According to powder Xray diffraction investigations and Rietveld refinement [space group I43m (no. 217), a = 8.2882(2) Å, R P = 0.03645, wR P = 0.04613], Sn 6 [P 12 N 24 ] crystallizes with a sodalite-type structure with a reduced occupation factor of 3/4 for the Sn atom at Wyckoff site 8c and an empty Wyckoff site 2a at the center of the β-cages. The structural results are further corroborated by energy-dispersive X-ray spectroscopy (EDX) analyses, so- [a]382 lid-state NMR spectroscopy, and theoretical investigations (DFT), including density of states (DOS), energy/volume, and electron localization (ELF) calculations. The 119 Sn Mössbauer spectrum shows a single, quadrupole-split signal for Sn II at an isomer shift of 3.05 mm/s. In addition to SiPN 3 with a defective wurtzite type of structure, the nitridophosphate sodalite Sn 6 [P 12 N 24 ] represents the second ternary nitridophosphate containing only p-block elements.

Mixed Tin Valence in the Tin(II/IV)‐Nitridophosphate Sn3P8N16

“…The difference between both network types is found in the connection between vierer ‐rings (Figure S2). P−N bonds of the PN 4 tetrahedra are between 1.572(4) and 1.679(4) Å, which is a typical range for nitridophosphates and comparable to e. g. Sn 6 [P 12 N 24 ] [23] . The Sn IV N 5 pyramid shows Sn−N distances between 2.110(4) and 2.140(4) Å, comparable to the Sn−N distances of [SnN 4 O 2 ] 12– octahedra in Sn 2 N 2 O [55] .…”

“…Nitrogen coordinated Sn IV also shows SnN 4 tetrahedra (e. g. in γ‐Sn 3 N 4 ), presumably SnN 5 trigonal bipyramids (in Sn 3 N 4 at around 25 GPa) and SnN 6 octahedra (e. g. in γ‐Sn 3 N 4 or SnN 2 ). Sn II is coordinated threefold in trigonal SnN 3 pyramids (e. g. in Sn 6 [P 12 N 24 ]) or fourfold in distorted square‐based SnN 4 pyramids (e. g. in Sn(CN 2 )) [22–26] …”

“…Combining the structural potential of nitridophosphates with the versatility of tin, unprecedented structure types with a widely increased field of applications can be expected. Currently, there is only a single compound in the Sn/P/N system, namely, the tin nitridophosphate Sn II 6 [P 12 N 24 ] [23] . It crystallizes in a sodalite‐type framework structure, foreshadowing the potential of tin nitridophosphates, considering the importance of zeolites in today's industry.…”

Sodalite‐type Ga16/3[P12N24]O2: Synthesis, Electron Crystallography and Powder X‐ray Diffraction

“…Among a plethora of synthetic materials that exhibit the sodalite structure type, there are several silicate‐analogous nitridophosphates and oxonitridophosphates. These include the M 4 P 6 N 12 S ( M =Cd, Mg), [4,5] Zn 7‐x H 2x [P 12 N 24 ]Cl 2 (0≤x≤3), [6,7] M 6+y/2−x H 2x [P 12 N 24 ] Z y ( M =Fe, Co, Ni, Mn; Z =Cl, Br, I; 0≤x≤4, y≤2), [8] Zn 8 [P 12 N 24 ] X 2 ( X =O, S, Se, Te), [9,10] M 8‐m H m [P 12 N 18 O 6 ]Cl 2 ( M =Cu, Li) [11] or Sn 6 [P 12 N 24 ] [12] . Structural similarities between (oxo‐)nitridophosphates and silicates have often been discussed, as they can easily be explained by the fact that the element combinations Si/O and P/N are isoelectronic.…”

“…These include the M 4 P 6 N 12 S (M = Cd, Mg), [4,5] Zn 7-x H 2x [P 12 N 24 ]Cl 2 (0 � x � 3), [6,7] M 6 + y/2À x H 2x [P 12 N 24 ]Z y (M = Fe, Co, Ni, Mn; Z = Cl, Br, I; 0 � x � 4, y � 2), [8] Zn 8 [P 12 N 24 ]X 2 (X = O, S, Se, Te), [9,10] M 8-m H m [P 12 N 18 O 6 ]Cl 2 (M = Cu, Li) [11] or Sn 6 [P 12 N 24 ]. [12] Structural similarities between (oxo-)nitridophosphates and silicates have often been discussed, as they can easily be explained by the fact that the element combinations Si/O and P/N are isoelectronic. The variable O/N ratio enables varying charge of the framework, so that it can adapt to cation charges.…”