Beryllium nitride

Beryllium nitride
Names

IUPAC name Beryllium nitride
Other names triberyllium dinitride
Identifiers
CAS Number	1304-54-7^Y
3D model (JSmol)	Interactive image Interactive image Interactive image
ECHA InfoCard	100.013.757
EC Number	215-132-6
UNII	P0T5F6IUK4
InChI InChI=1S/3Be.2N InChI=1S/3Be.2N/q3+2;2-3 InChI=1S/3Be.2N/q;;+2;2*-1
SMILES [Be]=N[Be]N=[Be] [Be+2].[Be+2].[Be+2].[N-3].[N-3] [Be]=[N-].[Be+2].[N-]=[Be]
Properties
Chemical formula	Be₃N₂
Molar mass	55.051 g·mol⁻¹
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	decomposes in solutions of acid and base
Structure
Crystal structure	Cubic, cI80, SpaceGroup = Ia-3, No. 206 (α form)
Hazards
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 0.002 mg/m³ C 0.005 mg/m³ (30 minutes), with a maximum peak of 0.025 mg/m³ (as Be)^[1]
REL (Recommended)	Ca C 0.0005 mg/m³ (as Be)^[1]
IDLH (Immediate danger)	Ca [4 mg/m³ (as Be)]^[1]
Related compounds
Other cations	Calcium nitride Magnesium nitride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is ^YN ?) Infobox references

Chemical compound

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 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

^ ^a ^b ^c NIOSH Pocket Guide to Chemical Hazards. "#0054". National Institute for Occupational Safety and Health (NIOSH).
^ ^a ^b ^c ^d ^e Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier ISBN 0-12-352651-5
^ Hugh O. Pierson, 1996, Handbook of Refractory Carbides and Nitrides: Properties, Characteristics, Processing, and Applications, William Andrew Inc.,ISBN 0-8155-1392-5
^ 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).