Biphenyl

From Wikipedia, the free encyclopedia

Biphenyl

Systematic name

Biphenyl

C₁₂H₁₀

154.21 g/mol

[92-52-4]

1.04 g/cm³

Solubility in Water

Insoluble

Melting point

68.9 °C

Boiling point

256 °C

SMILES

c1ccccc1(c2ccccc2)

Hazards

MSDS

External MSDS

EU classification

Irritant (Xi)
Dangerous for
the environment (N)

NFPA 704

R-phrases

R36/37/38, R50/53

S-phrases

S2, S23, S60, S61

Flash point

113 °C

Autoignition
temperature

540 °C

Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references

Biphenyl (or diphenyl or phenyl benzene or 1,1'-biphenyl or lemonene) is a solid organic compound that forms colorless to yellowish crystals. It has a distinctively pleasant smell. Biphenyl is an aromatic hydrocarbon with a molecular formula C₁₂H₁₀.

1 Properties
2 Use
3 Reference
4 External links

[edit] Properties

Biphenyl occurs naturally in coal tar, crude oil, and natural gas and can be produced from these sources by distillation. Biphenyl is insoluble in water, but soluble in typical organic solvents. The biphenyl molecule consists of two connected benzene rings, without any additional functionalization, and is therefore not very reactive. The flashpoint is 113 °C and the autoignition temperature is 540 °C. Substituted biphenyls can be prepared synthetically by various methods including the Suzuki reaction and the Ullmann reaction.

[edit] Use

Biphenyl prevents the growth of molds and fungus, and is therefore used as a preservative (E230, in combination with E231, E232 and E233), particularly in the preservation of citrus fruits during transportation.

Biphenyl is most 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 used as an intermediate for the production of a host of other organic compounds such as emulsifiers, optical brighteners, crop protection products, and plastics. Its biochemical degradation is under investigation.