Biaryl

Biphenyl

Names
Preferred IUPAC name 1,1'-Biphenyl
Other names Biphenyl Phenyl benzene
Identifiers
CAS Number	92-52-4 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:17097 Y
ChemSpider	6828 Y
ECHA InfoCard	100.001.967
E number	E230 (preservatives)
KEGG	C06588 Y
PubChem CID	7095
UNII	2L9GJK6MGN Y
InChI InChI=1S/C12H10/c1-3-7-11(8-4-1)12-9-5-2-6-10-12/h1-10H Y Key: ZUOUZKKEUPVFJK-UHFFFAOYSA-N Y InChI=1/C12H10/c1-3-7-11(8-4-1)12-9-5-2-6-10-12/h1-10H Key: ZUOUZKKEUPVFJK-UHFFFAOYAV
SMILES c1ccc(cc1)c2ccccc2
Properties
Chemical formula	C12H10
Molar mass	154.21 g·mol−1
Appearance	Colorless to pale-yellow crystals
Odor	pleasant
Density	1.04 g/cm3
Melting point	69.2 °C (156.6 °F; 342.3 K)
Boiling point	255 °C (491 °F; 528 K)
Solubility in water	4.45 mg/L
Vapor pressure	0.005 mmHg (20°C)
Magnetic susceptibility (χ)	-103.25·10−6 cm3/mol
Hazards
EU classification (DSD) (outdated)	Irritant (Xi) Dangerous for the environment (N)
R-phrases (outdated)	R36/37/38 R50/53
S-phrases (outdated)	(S2) S23 S60 S61
NFPA 704	1 1 0
Flash point	113 °C (235 °F; 386 K)
Autoignition temperature	540 °C (1,004 °F; 813 K)
Explosive limits	0.6%-5.8%
Lethal dose or concentration (LD, LC):
LD50 (median dose)	2400 mg/kg (oral, rabbit) 3280 mg/kg (oral, rat) 1900 mg/kg (oral, mouse) 2400 mg/kg (oral, rat)
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 1 mg/m3 (0.2 ppm)
REL (Recommended)	TWA 1 mg/m3 (0.2 ppm)
IDLH (Immediate danger)	100 mg/m3
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

Biphenyl (or diphenyl or phenylbenzene or 1,1′-biphenyl or lemonene) is an organic compound that forms colorless crystals. Particularly in older literature, compounds containing the functional group consisting of biphenyl less one hydrogen (the site at which it is attached) may use the prefixes xenyl or diphenylyl.

It has a distinctively pleasant smell. Biphenyl is an aromatic hydrocarbon with a molecular formula (C₆H₅)₂. It is notable as a starting material for the production of polychlorinated biphenyls (PCBs), which were once widely used as dielectric fluids and heat transfer agents.

Biphenyl is also an intermediate for the production of a host of other organic compounds such as emulsifiers, optical brighteners, crop protection products, and plastics. Biphenyl is insoluble in water, but soluble in typical organic solvents. The biphenyl molecule consists of two connected phenyl rings.

Biphenyl is produced industrially as a byproduct of the dealkylation of toluene to produce benzene:

The other principal route is by the oxidative dehydrogenation of benzene:

40,000,000 kg are produced annually by these routes.

In the laboratory, biphenyl can also be synthesized by treating phenylmagnesium bromide with copper salts.

Biphenyl occurs naturally in coal tar, crude oil, and natural gas and can be isolated from these sources via distillation.