Beryllium nitride explained

Beryllium nitride, Be3N2, is a nitride of beryllium. It can be prepared from the elements at high temperature (1100–1500 °C);[1] unlike beryllium azide or BeN6, it decomposes in vacuum into beryllium and nitrogen.[1] It is readily hydrolysed forming beryllium hydroxide and ammonia.[1] It has two polymorphic forms cubic α-Be3N2 with a defect anti-fluorite structure, and hexagonal β-Be3N2.[1] It reacts with silicon nitride, Si3N4 in a stream of ammonia at 1800–1900 °C to form BeSiN2.[1]

Preparation

Beryllium nitride is prepared by heating beryllium metal powder with dry nitrogen in an oxygen-free atmosphere in temperatures between 700 and 1400 °C.

3Be + N2 → Be3N2

Uses

It is used in refractory ceramics[2] as well as in nuclear reactors.

It is used to produce radioactive carbon-14 for tracer applications by the + n → + p reaction. It is favoured due to its stability, high nitrogen content (50%), and the very low cross section of beryllium for neutrons.[3]

Reactions

Beryllium nitride reacts with mineral acids producing ammonia and the corresponding salts of the acids:

Be3N2 + 6 HCl → 3 BeCl2 + 2 NH3

In strong alkali solutions, a beryllate forms, with evolution of ammonia:

Be3N2 + 6 NaOH → 3 Na2BeO2 + 2 NH3

Both the acid and alkali reactions are brisk and vigorous. Reaction with water, however, is very slow:

Be3N2 + 6 H2O → 3 Be(OH)2 + 2 NH3

Reactions with oxidizing agents are likely to be violent. It is oxidized when heated at 600 °C in air.

Notes and References

  1. Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier
  2. Hugh O. Pierson, 1996, Handbook of Refractory Carbides and Nitrides: Properties, Characteristics, Processing, and Applications, William Andrew Inc.,
  3. THE PRODUCTION OF C$sup 14$ BY THE Be$sub 3$N$sub 2$ PROCESS . Shields . R. P. . 1956-02-01 . Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States) . ORNL-1962 . English.