Beryllium Nitride

Beryllium nitride, Be₃N₂, is a beryllium nitride. It can be made at high temperatures (1100-1500 °C) from the elements, but unlike Beryllium azide or BeN₆, it decomposes in vacuum into beryllium and nitrogen. It hydrolyzes easily, producing beryllium hydroxide and ammonia. It exists in two polymorphic forms: cubic –Be₃N₂, which has a defect anti-fluorite structure, and hexagonal –Be₃N₂. At 1800-1900 °C, it reacts with silicon nitride, Si₃N₄, in an ammonia stream to form BeSiN₂.

Properties

• Chemical formula: Be₃N₂
• Molar mass|: 55.06 g/mol
• Appearance: yellow or white powder
• Density: 2.71 g/cm3
• Melting point: 2,200 °C (3,990 °F; 2,470 K)
• Boiling point: 2,240 °C (4,060 °F; 2,510 K) (decomposes)
• Solubility in water: decomposes
• Solubility in [acids, bases]: hydrolyzes
• Crystal structure: Cubic, cI80, SpaceGroup = Ia-3, No. 206 (α form)

Preparation

Beryllium nitride is a beryllium and nitrogen compound that is created by heating beryllium metal powder with dry nitrogen at high temperatures (1100-1500 °C). It is relatively reactive, oxidizing quickly in air at 600°C and decomposing in water.

Beryllium nitride is made by heating beryllium metal powder with dry nitrogen in an oxygen-free environment at temperatures ranging from 700 to 1400 °C.

3Be + N₂ → Be₃N₂

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.

Uses

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