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Tetrahedron‐based nitrides offer a wide range of properties and applications. Highly condensed nitridophosphates are examples of nitrides that exhibit fascinating luminescence properties when doped with Eu2+, making them appealing for industrial applications. Here, we present the first nitridomagnesophosphate solid solution series Ba3−xSrx[Mg2P10N20] : Eu2+ (x=0–3), synthesized by a high‐pressure high‐temperature approach using the multianvil technique (3 GPa, 1400 °C). Starting from the binary nitrides P3N5 and Mg3N2 and the respective alkaline earth azides, we incorporate Mg into the P/N framework to increase the degree of condensation κ to 0.6, the highest observed value for alkaline earth nitridophosphates. The crystal structure was elucidated by single‐crystal X‐ray diffraction, powder X‐ray diffraction, energy‐dispersive X‐ray spectroscopy (EDX), and solid‐state NMR. DFT calculations were performed on the title compounds and other related highly condensed nitridophosphates to investigate the influence of Mg in the P/N network. Eu2+‐doped samples of the solid solution series show a tunable narrow‐band emission from cyan to green (492–515 nm), which is attributed to the preferred doping of a single crystallographic site. Experimental confirmation of this assumption was provided by overdoping experiments and STEM‐HAADF studies on the series as well on the stoichiometric compound Ba2Eu[Mg2P10N20] with additional atomic resolution energy‐dispersive X‐ray spectroscopy (EDX) mapping. [ABSTRACT FROM AUTHOR]

A series of isostructural imidonitridophosphates AE2AlP8N15(NH) (AE=Ca, Sr, Ba) was synthesized at high‐pressure/high‐temperature conditions (1400 °C and 5–9 GPa) from alkaline‐earth metal nitrides or azides Ca3N2/Sr(N3)2/Ba(N3)2 and the binary nitrides AlN and P3N5. NH4F served as a hydrogen source and mineralizing agent. The crystal structures were determined by single‐crystal X‐ray diffraction and feature a three‐dimensional network of vertex‐sharing PN4‐tetrahedra forming diverse‐sized rings that are occupied by aluminum and alkaline earth ions. These structures represent another example of nitridophosphate‐based networks that simultaneously incorporate AlN6‐octahedra and alkaline‐earth‐centered polyhedra, with aluminum not participating in the tetrahedra network. They differ from previously reported ones by incorporating non‐condensed octahedra instead of strongly condensed octahedra units and contribute to the diversity of multicationic nitridophosphate network structures. The results are supported by atomic resolution EDX mapping, solid‐state NMR and FTIR measurements. Eu2+‐doped samples show strong luminescence with narrow emissions in the range of green to blue under UV excitation, marking another instance of Eu2+‐luminescence within imidonitridophosphates. [ABSTRACT FROM AUTHOR]

Tetrahedra‐based nitridophosphates show a rich structural chemistry, which can be further extended by incorporating cations in higher coordinated positions, for example, in octahedral voids or by substituting the nitrogen atoms in the network with other anions. Following this approach, SrAl5P4N10O2F3 was synthesized at high‐temperature and high‐pressure conditions using a multianvil press (1400 °C, 5 GPa) starting from Sr(N3)2, c‐PON, P3N5, AlN, and NH4F. SrAl5P4N10O2F3 crystallizes in space group I4‾m2 ${I\bar 4m2}$ with a=11.1685(2) and c=7.84850(10) Å. Atomic‐resolution EDX mapping with scanning transmission electron microscopy (STEM) indicates atom assignments, which are further corroborated by bond‐valence sum (BVS) calculations. Ten Al3+‐centered octahedra form a highly condensed tetra‐face‐capped octahedra‐based unit that is a novel structure motif in network compounds. A network of vertex‐sharing PN4 tetrahedra and chains of face‐sharing Sr2+‐centered cuboctahedra complement the structure. Eu2+‐doped SrAl5P4N10O2F3 shows blue emission (λem=469 nm, fwhm=98 nm; 4504 cm−1) when irradiated with UV light. [ABSTRACT FROM AUTHOR]

Tetrahedra‐based nitridophosphates show a rich structural chemistry, which can be further extended by incorporating cations in higher coordinated positions, for example, in octahedral voids or by substituting the nitrogen atoms in the network with other anions. Following this approach, SrAl5P4N10O2F3 was synthesized at high‐temperature and high‐pressure conditions using a multianvil press (1400 °C, 5 GPa) starting from Sr(N3)2, c‐PON, P3N5, AlN, and NH4F. SrAl5P4N10O2F3 crystallizes in space group I4‾m2 ${I\bar 4m2}$ with a=11.1685(2) and c=7.84850(10) Å. Atomic‐resolution EDX mapping with scanning transmission electron microscopy (STEM) indicates atom assignments, which are further corroborated by bond‐valence sum (BVS) calculations. Ten Al3+‐centered octahedra form a highly condensed tetra‐face‐capped octahedra‐based unit that is a novel structure motif in network compounds. A network of vertex‐sharing PN4 tetrahedra and chains of face‐sharing Sr2+‐centered cuboctahedra complement the structure. Eu2+‐doped SrAl5P4N10O2F3 shows blue emission (λem=469 nm, fwhm=98 nm; 4504 cm−1) when irradiated with UV light. [ABSTRACT FROM AUTHOR]