Terphenyls are a group of closely related
aromatic hydrocarbons
Aromatic compounds, also known as "mono- and polycyclic aromatic hydrocarbons", are organic compounds containing one or more aromatic rings. The parent member of aromatic compounds is benzene. The word "aromatic" originates from the past grouping ...
. Also known as diphenylbenzenes or triphenyls, they consist of a central
benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...
ring substituted with two
phenyl group
In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6 H5, and is often represented by the symbol Ph. Phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen ...
s. There are three
substitution patterns: ''ortho''-terphenyl,
''meta''-terphenyl, and ''para''-terphenyl. Commercial grade terphenyl is generally a mixture of the three
isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers.
Iso ...
s. This mixture is used in the production of
polychlorinated terphenyl
Polychlorinated terphenyls (PCTs) are a group of chlorine derivatives of terphenyls. They are chemically related to polychlorinated biphenyls and have similar chemical properties. They have very low electrical conductivity, high heat stability ...
s, which were formerly used as heat storage and transfer agents.
[''p''-Terphenyl]
at chemicalland21.com
''p''-Terphenyl is the most common isomer. It is used as a
laser dye
Laser dyes are dyes used as laser medium in a dye laser. Laser dyes include the coumarins and the rhodamines. Coumarin dyes emit in the green region of the spectrum, whereas rhodamine dyes are used for emission in the yellow-red. The color emi ...
and a
sunscreen
Sunscreen, also known as sunblock or sun cream, is a photoprotective topical product for the skin that mainly absorbs, or to a much lesser extent reflects, some of the sun's ultraviolet (UV) radiation and thus helps protect against sunburn and ...
ingredient.
[
File:ortho-terphenyl.png, ''ortho''-Terphenyl
File:meta-terphenyl.png, ''meta''-Terphenyl
File:para-terphenyl.png, ''para''-Terphenyl
]
See also
* Biphenyl
Biphenyl (also known as diphenyl, phenylbenzene, 1,1′-biphenyl, lemonene or BP) is an organic compound that forms colorless crystals. Particularly in older literature, compounds containing the functional group consisting of biphenyl less one ...
* Terpyridine
Terpyridine (2,2';6',2"-terpyridine, often abbreviated to Terpy or Tpy) is a heterocyclic compound derived from pyridine. It is a white solid that is soluble in most organic solvents. The compound is mainly used as a ligand in coordination chemist ...
* Terthiophene
Terthiophene is the organic compound with the formula 4H3Ssub>2C4H2S. It is an oligomer of the heterocycle thiophene, a shorter oligomer is dithienyl, and the parent polymer is polythiophene. In the most common isomer of terthiophene, two thien ...
References
{{reflist
External links
p-Terphenyl
at the Oregon Laser Medical Center
at Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health
Aromatic hydrocarbons
Phenyl compounds