Triphosphorus pentanitride

Phosphorus (V ) nitride

White, odorless and tasteless solid

Fixed

2.51 g · cm -3 ( 18 ° C)

Insoluble in water

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Triphosphorpentanitrid is an inorganic chemical compound of the phosphor from the group of nitrides.

Production and representation

Triphosphorpentanitrid can be obtained by reaction of Phosphorsulfidammoniakat P4S10 · NH3 14 with ammonia or hydrogen at high temperatures. This method was used in 1903 by Stock and Hoffmann first time. Also possible is the preparation by reaction of phosphonitrilic ( PNCl2 ) 3 with ammonia at 825 ° C. Both reactions proceed via several intermediate steps.

It can also be obtained by ammonolysis of phosphorus pentachloride at 780 ° C to give a colorless mixture of α - and β - P3N5 formed.

Phase-pure α - Triphosphorpentanitrid produced during the pyrolysis of [P (NH2 ) 4] I at 825 ° C.

Properties

Triphosphorpentanitrid is a white, odorless and tasteless solid that is insoluble in all solvents. It decomposes in vacuum at a high temperature in the elements. It decomposes on heating with water in a sealed tube at 180 ° C to form phosphoric acid and ammonia. With oxygen it reacts only at 600 ° C. From 800 ° C, the compound to phosphorus (III ) nitride and nitrogen decomposed.

Triphosphorpentanitrid comes under normal conditions in two modifications. The network structure of α - PN4 Triphosphorpentanitrid consisting of tetrahedrons, has similarities with the structure of silicon dioxide and silicon nitride. Surprisingly, however, occurs in α - Triphosphorpentanitrid also an edge linking PN4 tetrahedra. The recoverable at high pressures and temperatures, γ - form consists of tetragonal and PN4 PN5 tetrahedral units are linked via a nitrogen atom miteinerander. With lithium nitride reacts depending on the mixing ratio and temperature at various salt-like nitridophosphates as Li7PN4, Li12P3N9 or Li10P4N10.