Cubic boron nitride

Boron nitride
Names

IUPAC name Boron nitride
Identifiers
CAS Number	10043-11-5^Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:50883^Y
ChemSpider	59612^Y
ECHA InfoCard	100.030.111
EC Number	233-136-6
Gmelin Reference	216
MeSH	Elbor
PubChem	66227
RTECS number	ED7800000
UNII	2U4T60A6YD^N
InChI InChI=1S/BN/c1-2^Y Key: PZNSFCLAULLKQX-UHFFFAOYSA-N^Y InChI=1S/B2N2/c1-3-2-4-1 Key: AMPXHBZZESCUCE-UHFFFAOYSA-N InChI=1S/B3N3/c1-4-2-6-3-5-1 Key: WHDCVGLBMWOYDC-UHFFFAOYSA-N InChI=1/BN/c1-2 Key: PZNSFCLAULLKQX-UHFFFAOYAL
SMILES B#N
Properties
Chemical formula	BN
Molar mass	24.82 g·mol⁻¹
Appearance	Colorless crystals
Density	2.1 (hBN); 3.45 (cBN) g/cm³
Melting point	2,973 °C (5,383 °F; 3,246 K) sublimates (cBN)
Solubility in water	insoluble
Electron mobility	200 cm²/(V·s) (cBN)
Refractive index (n_D)	1.8 (hBN); 2.1 (cBN)
Structure
Crystal structure	hexagonal, sphalerite, wurtzite
Thermochemistry
Specific heat capacity (C)	19.7 J/K mol
Std molar entropy (S^o₂₉₈)	14.77 J/K mol
Std enthalpy of formation (Δ_fH^o₂₉₈)	-250.91 kJ/mol
Gibbs free energy (Δ_fG˚)	-226.8 kJ/mol
Hazards
EU classification (DSD)	Xi
R-phrases	R36/37
S-phrases	S26, S36
NFPA 704	0 0 0
Related compounds
Related compounds	Boron arsenide Boron carbide Boron phosphide Boron trioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N (what is ^YN ?)
Infobox references

Boron carbide
Boron phosphide
Boron trioxide

Boron nitride is a heat- and chemically resistant refractory compound of boron and nitrogen with the chemical formula BN. It exists in various crystalline forms that are isoelectronic to a similarly structured carbon lattice. The hexagonal form corresponding to graphite is the most stable and soft among BN polymorphs, and is therefore used as a lubricant and an additive to cosmetic products. The cubic (sphalerite structure) variety analogous to diamond is called c-BN; it is softer than diamond, but its thermal and chemical stability is superior. The rare wurtzite BN modification is similar to lonsdaleite and may even be harder than the cubic form.

Because of excellent thermal and chemical stability, boron nitride ceramics are traditionally used as parts of high-temperature equipment. Boron nitride has potential use in nanotechnology. Nanotubes of BN can be produced that have a structure similar to that of carbon nanotubes, i.e. graphene (or BN) sheets rolled on themselves, but the properties are very different.

Boron nitride exists in multiple forms that differ in the arrangement of the boron and nitrogen atoms, giving rise to varying bulk properties of the material.

The amorphous form of boron nitride (a-BN) is non-crystalline, lacking any long-distance regularity in the arrangement of its atoms. It is analogous to amorphous carbon.

All other forms of boron nitride are crystalline.

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