Calcium nitride

Calcium nitride is the inorganic compound with the chemical formula Ca₃N₂.^[1] It exists in various forms (isomorphs), α-calcium nitride being more commonly encountered.

Calcium nitride

Unit cell containing 31 nitride ions (red) and 48 calcium ions (white). Each nitride is surrounded by six calcium, and each calcium by four nitride ions.
Names
IUPAC name Calcium nitride
Other names tricalcium dinitride
Identifiers
CAS Number	12013-82-0 Y
3D model (JSmol)	Interactive image Interactive image Interactive image
ChemSpider	10617534
ECHA InfoCard	100.031.435
EC Number	234-592-9
PubChem CID	3387080
CompTox Dashboard (EPA)	DTXSID30892172
InChI InChI=1S/3Ca.2N InChI=1S/3Ca.2N/q3*+2;2*-3 InChI=1S/3Ca.2N/q;;+2;2*-1
SMILES [Ca]=N[Ca]N=[Ca] [Ca+2].[Ca+2].[Ca+2].[N-3].[N-3] [Ca]=[N-].[Ca+2].[N-]=[Ca]
Properties
Chemical formula	Ca3N2
Molar mass	148.248 g·mol−1
Appearance	red-brown crystalline solid
Density	2.670 g/cm3 2.63 g/cm3 (17 °C)
Melting point	1,195 °C (2,183 °F; 1,468 K)
Solubility in water	decomposes
Structure
Crystal structure	Cubic, cI80
Space group	Ia-3, No. 206
Related compounds
Other anions	Calcium fluoride Calcium oxide
Other cations	Beryllium nitride Magnesium nitride Strontium nitride Barium nitride Radium nitride Zinc nitride Aluminium nitride Lithium nitride Sodium nitride Potassium nitride
Related compounds	Ammonia Calcium amide Calcium imide
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

Structure

α-Calcium nitride adopts an anti-bixbyite structure, similar to Mn₂O₃, except that the positions of the ions are reversed: calcium (Ca²⁺) take the oxide (O²⁻) positions and nitride ions (N³⁻) the manganese (Mn³⁺). In this structure, Ca²⁺ occupies tetrahedral sites, and the nitride centres occupy two different types of octahedral sites.^[2]

Synthesis and reactions

Calcium nitride is formed along with the oxide, CaO, when calcium burns in air. It can be produced by direct reaction of the elements:^[3]

3 Ca + N₂ → Ca₃N₂

It reacts with water or even the moisture in air to give ammonia and calcium hydroxide:^[4]

Ca₃N₂ + 6 H₂O → 3 Ca(OH)₂ + 2 NH₃

Like sodium oxide, calcium nitride absorbs hydrogen above 350 °C:

Ca₃N₂ + 2 H₂ → 2 CaNH + CaH₂

General references

• Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.