Beryllium nitride, Be3N2, is a nitride of beryllium. It can be prepared from the elements at high temperature (1100–1500 °C);[2] unlike beryllium azide or BeN6, it decomposes in vacuum into beryllium and nitrogen.[2] It is readily hydrolysed forming beryllium hydroxide and ammonia.[2] It has two polymorphic forms cubic α-Be3N2 with a defect anti-fluorite structure, and hexagonal β-Be3N2.[2] It reacts with silicon nitride, Si3N4 in a stream of ammonia at 1800–1900 °C to form BeSiN2.[2]

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[3] as well as in nuclear reactors.

It is used to produce radioactive carbon-14 for tracer applications by the 14
7N + n → 14
6C + p reaction. It is favoured due to its stability, high nitrogen content (50%), and the very low capture cross section of beryllium for neutrons.[4]

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.

References

  1. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0054". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ a b c d e Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier ISBN 0-12-352651-5
  3. ^ Hugh O. Pierson, 1996, Handbook of Refractory Carbides and Nitrides: Properties, Characteristics, Processing, and Applications, William Andrew Inc.,ISBN 0-8155-1392-5
  4. ^ Shields, R. P. (1956-02-01). THE PRODUCTION OF C$sup 14$ BY THE Be$sub 3$N$sub 2$ PROCESS (Report). Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). OSTI 4324224.


Allikas: https://en.wikipedia.org/wiki/Beryllium_nitride
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