Acenaphthene is a

polycyclic aromatic hydrocarbon A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. ...

(PAH) consisting of naphthalene with an ethylene bridge connecting positions 1 and 8. It is a colourless solid.

Coal tar Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It is a type of creosote. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psorias ...

consists of about 0.3% of this compound.

Production and reactions

Acenaphthene was prepared the first time from coal tar by

Marcellin Berthelot Pierre Eugène Marcellin Berthelot (; 25 October 1827 – 18 March 1907) was a French chemist and Republican politician noted for the ThomsenBerthelot principle of thermochemistry. He synthesized many organic compounds from inorganic substa ...

. Later Berthelot and Bardy synthesized the compound by cyclization of α-ethylnaphthalene. Industrially, it is still obtained from coal tar together with its derivative

acenaphthylene Acenaphthylene, a polycyclic aromatic hydrocarbon is an ortho- and peri-fused tricyclic hydrocarbon. The molecule resembles naphthalene with positions 1 and 8 connected by a -CH=CH- unit. It is a yellow solid. Unlike many polycyclic aromatic hyd ...

(and many other compounds). Like other

arene 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 groupin ...

s, acenaphthene forms complexes with low valent metal centers. One example is (η⁶-acenaphthene)Mn(CO)₃]⁺.

Uses

It is used on a large scale to prepare naphthalene dicarboxylic anhydride, which is a precursor to dyes and

optical brightener Optical brighteners, optical brightening agents (OBAs), fluorescent brightening agents (FBAs), or fluorescent whitening agents (FWAs), are chemical compounds that absorb light in the ultraviolet and violet region (usually 340-370 nm) of the ...

s. Naphthalene dicarboxylic anhydride is the precursor to

perylenetetracarboxylic dianhydride Perylenetetracarboxylic dianhydride (PTCDA) is an organic dye molecule and an organic semiconductor. It is used as a precursor to a class of molecules known as Rylene dyes, which are useful as pigments and dyes. It is a dark red solid with low s ...

, precursor to several commercial

pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...

s and dyes.K. Hunger. W. Herbst "Pigments, Organic" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2012. Greene, M. "Perylene Pigments" in High Performance Pigments, 2009, Wiley-VCH, Weinheim. pp. 261-274. : Pig29route

References

{{Authority control Polycyclic aromatic hydrocarbons Tricyclic compounds