Polycyclic aromatic hydrocarbons, also known as PAH, are chemical compounds that consist of fused aromatic rings and that do not contain heteroatoms and that do not carry substituents. Many of them are known or suspected carcinogens. They are formed by incomplete combustion of carbon-containing fuels such as wood, coal, diesel, fat, or tobacco.
PAH composed only of six-membered rings are called benzenoid PAH. The name comes from benzene, an aromatic hydrocarbon with a single, six-membered ring. The set of benzenoid PAH is closely related to a set of mathematical entities called polyhexes, which are planar figures composed by conjoining regular hexagons of identical size.
Examples of polycyclic aromatic hydrocarbons are naphthalene, anthracene, phenanthrene, pyrene, benzopyrene, and coronene.
External links
- [1] Database of PAH structures.