[en] Nitridophosphates and imidonitridophosphates show intriguing structural diversity, including unprecedented structure types. Highly condensed strontium imidonitridophosphate SrP₃N₅NH has been synthesized at 8 GPa and 1100 C using a high-pressure high-temperature approach starting from stoichiometric amounts of Sr(N₃)₂, P₃N₅ and NH₄Cl. Herein, NH₄Cl was used as a hydrogen source and as a precursor for in situ formation of SrCl₂, which acts as mineralizer and facilitates growth of single-crystals with a diameter of ≤30 μm. SrP₃N₅NH (P2₁/c (no. 14), a=5.01774(2), b=8.16912(4), c=12.70193(5) Aa, β=101.7848(3) , Z=4) adopts an unprecedented network structure, represented by the point symbol (3.4.5.6.7²)(3.4.5.7².8)(3.6.7³.8). This unique three nodal P/N(H) network is stabilized by moderately strong hydrogen bonds causing a structure-directing effect, which has not yet been reported for imidonitridophosphates. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

[en] Owing to intriguing materials properties non-metal nitrides are of special interest for both, solid-state chemistry and materials science. Mixed ternary non-metal nitrides, however, have only been sparsely investigated, as preparative chemistry lacks a systematic access, yet. Herein, we report on the highly condensed boron phosphorus nitride BP₃N₆, which was synthesized from (PNCl₂)₃, NH₄N₃ and h-BN in a high-pressure high-temperature reaction. By increasing partial pressure of HCl during synthesis using NH₄Cl, single-crystals of BP₃N₆ up to 80 μm in length were obtained. The unprecedented framework-type structure determined by single-crystal XRD blends structural motifs of both, α-P₃N₅ and c-BN, rendering BP₃N₆ a double nitride. The compound was further investigated by Rietveld refinement, EDX, temperature-dependent PXRD, FTIR and solid-state NMR spectroscopy. The formation of BP₃N₆ through use of reactive precursors exemplifies an innovative access to mixed non-metal nitrides. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

[en] Owing to its outstanding elastic properties, the nitride spinel γ‐Si${}_3$N${}_4$ is of considered interest for materials scientists and chemists. DFT calculations suggest that Si${}_3$N${}_4$‐analog beryllium phosphorus nitride BeP${}_2$N${}_4$ adopts the spinel structure at elevated pressures as well and shows outstanding elastic properties. Herein, we investigate phenakite‐type BeP${}_2$N${}_4$ by single‐crystal synchrotron X‐ray diffraction and report the phase transition into the spinel‐type phase at 47 GPa and 1800 K in a laser‐heated diamond anvil cell. The structure of spinel‐type BeP${}_2$N${}_4$ was refined from pressure‐dependent in situ synchrotron powder X‐ray diffraction measurements down to ambient pressure, which proves spinel‐type BeP${}_2$N${}_4$ a quenchable and metastable phase at ambient conditions. Its isothermal bulk modulus was determined to 325(8) GPa from equation of state, which indicates that spinel‐type BeP${}_2$N${}_4$ is an ultraincompressible material. (© 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)