CdP₂N₄ and MnP₂N₄ – Ternary Transition‐Metal Nitridophosphates

Abstract

The ternary transition-metal nitridophosphates CdP 2 N 4 and MnP 2 N 4 have been synthesized under high-pressure high-temperature conditions (5-8 GPa, 1000-1300°C) by using the multianvil technique. Cd and Mn azides can be used as the starting materials, however, with respect to safety considerations, it is much more advantageous to start from metal powders and phosphorus nitride imide, HPN 2 . Both nitridophosphates crystallize in a structure closely related to the mega calsilite structure type. As a result of the known issues concerning superstructures with this type of structure, TEM investigations were performed on CdP 2 N 4 , which revealed that the megacalsilite superstructure is not equally pronounced in all [a]

SrH4P6N12 and SrP8N14: Insights into the Condensation Mechanism of Nitridophosphates under High Pressure

“…[2][3][4][5][6][7][8][9][10] Additionally,t he high-pressure polymorphs g-P 3 N 5 and g-HP 4 N 7 featurePin penta-coordination spheres of square pyramids and trigonal bi-pyramids, respectively. [19][20][21][22] Recently,h igh-pressure metathesis has been established as another promising approach forrare-earth metal nitridophosphates. [11] In multinary systems, potentialHbridges may additionally influence the P/N network, as indicated by rare structural motifs like adamantane type[ P 4 N 10Àx (NH) x ] (10Àx)À cages in Rb 8 [P 4 N 6 (NH) 4 ](NH 2 ) 2 and Na 10 [P(NH) 6 N 4 ](NH 2 ) 6 (NH 3 ) 0.5 .…”

Nitridophosphates: A Success Story of Nitride Synthesis

“…Moreover,a ni ncreased reactivity might be ascribed to the azides because of the in situ formation of the metal nitrides, similar to the use of carbonates for oxide synthesis. [30,31,[65][66][67] By using ammonium azide NH 4 N 3 ,anitridic clathrate P 4 N 4 (NH) 4 (NH 3 )w ith trapped ammonia molecules has been obtained [Eq. These are especially interesting as the element combination PN 2 À is isoelectronic to SiO 2 and often forms (alumo)silicate-related frameworks.…”

“…Thecompounds MP 2 N 4 with M = Ca, Sr, Mn, Cd all crystallize as megakalsilite-type (KAlSiO 4 )structures,NaPN 2 in afilled b-cristobalite type,and BaP 2 N 4 in the high-pressure CaB 2 O 4type structure (Figure 10). [30,31,[65][66][67] By using ammonium azide NH 4 N 3 ,anitridic clathrate P 4 N 4 (NH) 4 (NH 3 )w ith trapped ammonia molecules has been obtained [Eq. (12)],w hich has been discussed as ag as-storage material.…”

Nitridophosphate – eine Erfolgsgeschichte der Nitridsynthese

“…(1)] auf die Nitridseite verlagern würde. [30,31,[65][66][67] Mit Ammoniumazid NH 4 N 3 erhält man das nitridische Clathrat P 4 N 4 -(NH) 4 (NH 3 ), das in Hohlräumen gefangene Ammoniakmoleküle beherbergt und daher als mçgliches Gasspeichermaterial diskutiert wurde [Gl. [30,31] Hochkondensierte Raumnetze mit k = 1/2 lassen sich mit der Azidroute direkt herstellen.…”

“…Solche Raumnetze sind von besonderem Interesse,d ad ie Elementkombination PN 2 À isoelektronisch zu SiO 2 ist und daher den (Alumo)silicaten verwandte Strukturen gebildet werden. So kristallisieren die Verbindungen der Summenformel MP 2 N 4 mit M = Ca, Sr, Mn, Cd im Megakalsilit-Typ,w ährend NaPN 2 einen aufge- [30,31,[65][66][67] Mit Ammoniumazid NH 4 N 3 erhält man das nitridische Clathrat P 4 N 4 -(NH) 4 (NH 3 ), das in Hohlräumen gefangene Ammoniakmoleküle beherbergt und daher als mçgliches Gasspeichermaterial diskutiert wurde [Gl. (12)].…”