Beryllium nitride

Beryllium nitride
Identifiers
CAS number	1304-54-7 Y
	Properties
Molecular formula	Be3N2
Molar mass	55.06 g/mol
Appearance	yellow or white powder
Density	2.71 g/cm3
Melting point	2200 °C
Boiling point	2240 °C (decomp)
Solubility in water	hydrolyzes
Structure
Crystal structure	Cubic, cI80, SpaceGroup = Ia-3, No. 106 (α form)
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Beryllium nitride, Be₃N₂, is a nitride of beryllium. It can be prepared from the elements at high temperature (1100–1500 °C),^[1] different 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.

Uses

It is used in refractory ceramics^[2] as well as in nuclear reactors and to produce radioactive carbon-14 for tracer applications.

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