Post‐Synthetic Modification: Systematic Study on a Simple Access to Nitridophosphates

Abstract

Nitridophosphates are a well-studied class of nitrides with diverse materials properties, such as luminescence or ion conductivity. Despite the growing interest in this compound class, their synthesis mostly works through direct combination of starting materials. Herein, we present a systematic study on a promising method for post-synthetic modification by treating pre-synthesized nitridophosphates with halides under elevated pressures and temperatures. Herein, we focus on the applicability of this approach to P/N compounds with different degrees of condensation. Accordingly, BaP 2 N 4 , Ba 3 P 5 N 10 Br, SrH 4 P 6 N 12 , CaP 8 N 14 , and Ca 2 PN 3 are investigated as model compounds for framework-, layer-, and chain-type nitridophosphates. The formation of structurally related, as well as, completely unrelated compounds, compared to the starting materials, shows the great potential of the approach, which increases the synthetic possibilities for nitridophosphates significantly.

Tunable Narrow‐Band Cyan‐Emission of Eu2+‐doped Nitridomagnesophosphates Ba3−xSrx[Mg2P10N20] : Eu2+ (x=0–3)

“…Since magnesium participates in the tetrahedral anionic framework as a NFC, AE 3 [Mg 2 P 10 N 20 ] exhibits the hitherto highest degree of condensation in multinary nitridophosphates, with k = n(NFC) : n(N) = 0.6 (k max, obs = 0.57 in HP 4 N 7 , MP 4 N 7 (M = Li, Na, K, Rb, Cs), AEP 8 N 14 (AE = Mg, Ca, Sr, Ba). [9,[17][18][19][20] The anionic 3D framework of the crystal structure is based of all-side vertex-sharing Q 4type MgN [3] 4 , PN [2] 3 N [3] and PN [2] 2 N [3] 2 tetrahedra (superscripted coordination numbers in square brackets, Figure 1A). Focusing only on the P/N framework, two striking structural motifs become apparent.…”

Post‐Synthetic Modification: Systematic Study on a Simple Access to Nitridophosphates

“…The obtained MgP 8 N 14 has previously not been accessible by conventional synthesis and its structure was now elucidated from powder diffraction data, with a detailed discussion provided in the Supporting Information ( Figures S8 and S9, Table S7). [36] The closely similar structures of AEP 8 N 14 (AE = Mg, Ca) indicate a topotactic reaction, which might be realized through the highly-condensed quadruple layers of CaP 8 N 14 with (k = 0.57). Thus, the PN 4 tetrahedra layers are assumed to be rather rigid, while Ca 2+ ions in between remain mobile and easily accessible.…”

Nitride Synthesis under High-Pressure, High-Temperature Conditions: Unprecedented In Situ Insight into the Reaction

“…38 Transferring the well-known ion exchange to high-pressure, high-temperature syntheses, it was shown that a preservation of a P/N framework is possible. 46 Recently, in situ-generated HCl and HF were used to activate inert starting materials such as BN or even TiN. 43,44 It is assumed that reactive intermediate species are formed during the reaction process.…”