Polycyclic aromatic hydrocarbons

Naphthalene is an organic compound with the chemical formula . It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. It is the main ingredient of traditional mothballs.

Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings. It is a component of coal tar. Anthracene is used in the production of the red dye alizarin and other dyes, as a scintillator to detect high energy particles, as production of pharmaceutical drugs. Anthracene is colorless but exhibits a blue (400–500 nm peak) fluorescence under ultraviolet radiation.

Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C14H10, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics, pesticides, explosives, and drugs. It has also been used to make bile acids, cholesterol and steroids.

hydrocarbons composed of multiple aromatic rings

'Benzo[a]pyrene (BaP or B[a]P') is a polycyclic aromatic hydrocarbon and the result of incomplete combustion of organic matter at temperatures between and . The ubiquitous compound can be found in coal tar, tobacco smoke and many foods, especially grilled meats. The substance with the formula C20H12 is one of the benzopyrenes, formed by a benzene ring fused to pyrene. Its diol epoxide metabolites, more commonly known as BPDE, react with and bind to DNA, resulting in mutations and eventually cancer. It is listed as a Group 1 carcinogen by the IARC. In the 18th century a scrotal cancer of chimne

Azulene is an aromatic organic compound and an isomer of naphthalene. Naphthalene is colourless, whereas azulene is dark blue. The compound is named after its colour, as "azul" is Spanish for blue. Two terpenoids, vetivazulene (4,8-dimethyl-2-isopropylazulene) and guaiazulene (1,4-dimethyl-7-isopropylazulene), that feature the azulene skeleton are found in nature as constituents of pigments in mushrooms, guaiac wood oil, and some marine invertebrates.

Acenaphthene is a polycyclic aromatic hydrocarbon (PAH) consisting of naphthalene with an ethylene bridge connecting positions 1 and 8. It is a colourless solid. Coal tar consists of about 0.3% of this compound.

Pyrene is a polycyclic aromatic hydrocarbon (PAH) consisting of four fused benzene rings, resulting in a flat aromatic system. The chemical formula is . This yellow-green solid is the smallest peri-fused PAH (one where the rings are fused through more than one face). Pyrene forms during incomplete combustion of organic compounds.

Fluorene , or '9H-fluorene' is an organic compound with the formula (C6H4)2CH2. It forms white crystals that exhibit a characteristic, aromatic odor similar to that of naphthalene. Despite its name, it does not contain the element fluorine, but rather it comes from the violet fluorescence it exhibits. For commercial purposes it is obtained from coal tar, where it was discovered and named by Marcellin Berthelot in 1867.

Tetracene, also called naphthacene, is a polycyclic aromatic hydrocarbon. It has the appearance of a pale orange powder. Tetracene is the four-ringed member of the series of acenes.

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 hydrocarbons, it has no fluorescence.

Pentacene () is a polycyclic aromatic hydrocarbon consisting of five linearly-fused benzene () rings. This highly conjugated compound is an organic semiconductor. The compound generates excitons upon absorption of ultra-violet (UV) or visible light; this makes it very sensitive to oxidation. For this reason, this compound, which is a purple powder, slowly degrades upon exposure to air and light.

Perylene or perilene is a polycyclic aromatic hydrocarbon with the chemical formula C20H12, occurring as a brown solid. It or its derivatives may be carcinogenic, and it is considered to be a hazardous pollutant. In cell membrane cytochemistry, perylene is used as a fluorescent lipid probe. It is the parent compound of a class of rylene dyes.

Chrysene is a polycyclic aromatic hydrocarbon (PAH) with the molecular formula that consists of four fused benzene rings. It is a natural constituent of coal tar, from which it was first isolated and characterized. It is also found in creosote at levels of 0.5–6 mg/kg.

Fluoranthene is a polycyclic aromatic hydrocarbon (PAH). The molecule can be viewed as the fusion of naphthalene and benzene unit connected by a five-membered ring. The chemical formula is . Although samples are often pale yellow, the compound is colorless. It is soluble in nonpolar organic solvents. It is a member of the class of PAHs known as non-alternant PAHs because it has rings other than those with six carbon atoms. It is a structural isomer of the alternant PAH pyrene. It is not as thermodynamically stable as pyrene. Its name is derived from its fluorescence under UV light.

Coronene (also known as superbenzene and cyclobenzene) is a polycyclic aromatic hydrocarbon (PAH) comprising seven peri-fused benzene rings. Its chemical formula is . It is a yellow material that dissolves in common solvents including benzene, toluene, and dichloromethane. Its solutions emit blue light fluorescence under UV light. It has been used as a solvent probe, similar to pyrene.

thumb|The general structural formula for acenes

Picene is a hydrocarbon found in the pitchy residue obtained in the distillation of peat tar and of petroleum. This is distilled to dryness and the distillate repeatedly recrystallized from cymene. It may be synthetically prepared by the action of anhydrous aluminium chloride on a mixture of naphthalene and 1,2-dibromoethane, or by distilling a-dinaphthostilbene. It crystallizes in large colorless plates which possess a blue fluorescence. It is soluble in concentrated sulfuric acid with a green color. Chromic acid in glacial acetic acid solution oxidizes it to picene-quinone, picene-quinone ca

'1H-Phenalene, often called simply phenalene' is a polycyclic aromatic hydrocarbon (PAH). Like many PAHs, it is an atmospheric pollutant formed during the combustion of fossil fuels. It is the parent compound for the phosphorus-containing phosphaphenalenes.

Triphenylene is an organic compound with the formula (C6H4)3. It is a flat polycyclic aromatic hydrocarbon (PAH) that has a highly symmetric and planar structure consists of four fused benzene rings. Triphenylene has delocalized 18-π-electron systems based on a planar structure, corresponding to the symmetry group D3h. It is more resonance stable than its isomers chrysene, [[Benz(a)anthracene|benz[a]anthracene]], [[Benzo(c)phenanthrene|benzo[c]phenanthrene]], and tetracene, hence resists hydrogenation. It is a light yellow powder, insoluble in water.

'Benz[a]anthracene or benzo[a]anthracene' is a polycyclic aromatic hydrocarbon with the chemical formula C18H12. It is produced during incomplete combustion of organic matter.

Ovalene is a polycyclic aromatic hydrocarbon with the formula C32H14, which consists of ten peri-fused six-membered rings. It is very similar to coronene.

Tetraphenylene is an organic compound, solid at room temperature, with the chemical formula C24H16. It is a member of the unsaturated polycyclic hydrocarbons class of compounds and a tetramer of benzyne.

Hexacene is an aromatic compound consisting of six linearly-fused benzene rings. It is a blue-green, air-stable solid with low solubility.

'Benzo[e]pyrene' is a polycyclic aromatic hydrocarbon with the chemical formula C20H12. It is listed as a Group 3 carcinogen by the IARC.

Olympicene is an organic carbon-based molecule formed of five rings, of which four are benzene rings, joined in the shape of the Olympic rings.

Kekulene is a polycyclic aromatic hydrocarbon which consists of 12 fused benzene rings arranged in a circle. It is therefore classified as a [12]-circulene with the chemical formula C48H24. It was first synthesized in 1978, and was named in honor of August Kekulé, the discoverer of the structure of the benzene molecule.

Rubrene (5,6,11,12-tetraphenyltetracene) is the organic compound with the formula . It is a red colored polycyclic aromatic hydrocarbon. Because of its distinctive optical and electrical properties, rubrene has been extensively studied. It has been used as a sensitiser in chemoluminescence and as a yellow light source in lightsticks.

thumb|Benzopyrene with a purity of over 98%, with a Russian ruble for scale [[File:Benzo-a-pyrene.svg|thumb|right|Chemical structure of benzo[a]pyrene|200px]] [[File:Benzo(e)pyrene.png|thumb|right|Chemical structure of benzo[e]pyrene|125px]] A benzopyrene is an organic compound with the formula C20H12. Structurally speaking, the colorless isomers of benzopyrene are pentacyclic hydrocarbons and are fusion products of pyrene and a phenylene group. Two isomeric species of benzopyrene are [[benzo(a)pyrene|benzo[a]pyrene]] and the less common [[benzo(e)pyrene|benzo[e]pyrene]]. They belong to the ch

Corannulene is a polycyclic aromatic hydrocarbon with chemical formula C20H10. The molecule consists of a cyclopentane ring fused with 5 benzene rings, so another name for it is [5]circulene. It is of scientific interest because it is a geodesic polyarene and can be considered a fragment of buckminsterfullerene. Due to this connection and also its bowl shape, corannulene is also known as a buckybowl. Buckybowls are fragments of buckyballs. Corannulene exhibits a bowl-to-bowl inversion with an inversion barrier of 10.2 kcal/mol (42.7 kJ/mol) at −64 °C.

right|thumb|150px|Hexahelicene [[File:Helicenegeneral.svg|right|thumb|150px|General structure formula of [n]helicene]] In organic chemistry, helicenes are ortho-condensed polycyclic aromatic compounds in which benzene rings or other aromatics are angularly annulated to give helically-shaped chiral molecules. The chemistry of helicenes has attracted continuing attention because of their unique structural, spectral, and optical features.

Heptacene is an organic compound and a polycyclic aromatic hydrocarbon and the seventh member of the acene or polyacene family of linear fused benzene rings. This compound has long been pursued by chemists because of its potential interest in electronic applications and was first synthesized but not cleanly isolated in 2006. Heptacene was finally fully characterized in bulk by researchers in Germany and the United States in 2017.

Benzocyclobutene (BCB) is a benzene ring fused to a cyclobutane ring. It has chemical formula .

'Benzo[c]phenanthrene' is a polycyclic aromatic hydrocarbon with the chemical formula . It is a white solid that is soluble in nonpolar organic solvents. It is a nonplanar molecule consisting of the fusion of four fused benzene rings. The compound is of mainly theoretical interest but it is environmentally occurring and weakly carcinogenic.

Tricyclobutabenzene is an aromatic hydrocarbon consisting of a benzene core with three cyclobutane rings fused onto it. This compound and related compounds are studied in the laboratory because they often display unusual conformations and because of their unusual reactivity. Tricyclobutabenzenes are isomers of radialenes and form an equilibrium with them.

Anthanthrene (dibenzo[def,mno]chrysene) is a polycyclic aromatic hydrocarbon (PAH) primarily formed during the incomplete combustion of organic materials such as fossil fuels, wood, and tobacco. It is a golden-yellow, odorless solid, and is often released as solid particulate matter attached to soot or aerosols. Unlike other PAH molecules, it lacks a "bay region", a structural pocket that increases reactivity of the molecule. Due to its high lipophilicity, anthanthrene has low water-solubility, and tends to accumulate in lipid-rich environments.

'Benzo[ghi]perylene' is a polycyclic aromatic hydrocarbon with the chemical formula C22H12.

Hypothesis about the origin of life

Sumanene is a polycyclic aromatic hydrocarbon and of scientific interest because the molecule can be considered a fragment of buckminsterfullerene. Due to this connection and also its bowl shape, Sumanene is also known as a buckybowl. Suman means "flower" in both Hindi and Sanskrit. The core of the arene is a benzene ring and the periphery consists of alternating benzene rings (3) and cyclopentadiene rings (3). Unlike fullerene, sumanene has benzyl positions which are available for organic reactions.

Zethrene ('''''') is a polycyclic aromatic hydrocarbon consisting of two phenalene units fused together. According to Clar's rule, the two exterior naphthalene units are truly aromatic and the two central double bonds are not aromatic at all. For this reason the compound is of some interest to academic research. Zethrene has a deep-red color and it is light sensitive - complete decomposition under a sunlight lamp occurs within 12 hours. The melting point is 262 °C.

Biphenylene is an organic compound with the formula (C6H4)2. It is a pale, yellowish solid with a hay-like odor. Despite its unusual structure, it behaves like a traditional polycyclic aromatic hydrocarbon.

Diindenoperylene (DIP) is an organic semiconductor which receives attention because of its potential application in optoelectronics (solar cells, OLEDs) and electronics (RFID tags). DIP is a planar perylene derivative with two indeno-groups attached to opposite sides of the perylene core. Its chemical formula is C32H16, the full chemical name is diindeno[1,2,3-cd:1',2',3'-lm]perylene. Its chemical synthesis has been described.

'7,12-Dimethylbenz[a]anthracene (DMBA') is an immunosuppressor and a powerful organ-specific laboratory carcinogen. DMBA is widely used in many research laboratories studying cancer. DMBA serves as a tumor initiator. Tumor promotion can be induced with treatments of 12-O-tetradecanoylphorbol-13-acetate (TPA) in some models of two-stage carcinogenesis. This allows for a greatly accelerated rate of tumor growth, making many cancer studies possible.

'Benzo[j]fluoranthene' (BjF) is an organic compound with the chemical formula C20H12. Classified as a polycyclic aromatic hydrocarbon (PAH), it is a colourless solid that is poorly soluble in most solvents. Impure samples can appear off white. Closely related isomeric compounds include [[benzo(a)fluoranthene|benzo[a]fluoranthene]] (BaF), [[benzo(b)fluoranthene|benzo[b]fluoranthene]] (BbF), [[benzo(e)fluoranthene|benzo[e]fluoranthene]] (BeF), and [[benzo(k)fluoranthene|benzo[k]fluoranthene]] (BkF). BjF is present in fossil fuels and is released during incomplete combustion of organic matter. It

'Benzo[k]fluoranthene 'is an organic compound with the chemical formula C20H12. Classified as a polycyclic aromatic hydrocarbon (PAH), it forms pale yellow needles or crystals, and is poorly soluble in most solvents. Impure samples can appear off white. Closely related isomeric compounds include benzo(a)fluoranthene, benzo(b)fluoranthene, benzo(e)fluoranthene, and benzo(j)fluoranthene.

Triptycene is an aromatic hydrocarbon, the simplest iptycene molecule with the formula C2H2(C6H4)3. It is a white solid that is soluble in organic solvents. The compound has a paddle-wheel configuration with D3h symmetry. It is named after the medieval three-piece art panel, the triptych. Several substituted triptycenes are known. Barrelenes are structurally related. Due to the rigid framework and three-dimensional geometry, derivatives of triptycene have been well researched.

Methylcholanthrene is a highly carcinogenic polycyclic aromatic hydrocarbon produced by burning organic compounds at very high temperatures. Methylcholanthrene is also known as 3-methylcholanthrene, 20-methylcholanthrene or the IUPAC name 3-methyl-1,2-dyhydrobenzo[j]aceanthrylene. The short notation often used is 3-MC or MCA. This compound forms pale yellow solid crystals when crystallized from benzene and ether. It has a melting point around 180 °C and its boiling point is around 280 °C at a pressure of 80 mmHg. Methylcholanthrene is used in laboratory studies of chemical carcinogen

'Dibenz[a,h]anthracene, Benzo[k]tetraphene or 1,2:5,6-Dibenzanthracene' is an organic compound with the chemical formula C22H14. It is a polycyclic aromatic hydrocarbon (PAH) made of five fused benzene rings. It is a fused five-ringed PAH which is common as a pollutant of smoke and oils. It is stable and highly genotoxic in bacterial and mammalian cell systems, as it intercalates into DNA and causes mutations.

5,12-Bis(phenylethynyl)naphthacene is a fluorescent dye used in lightsticks. It yields orange light.

Retene, methyl isopropyl phenanthrene or 1-methyl-7-isopropyl phenanthrene, C18H18, is a polycyclic aromatic hydrocarbon present in the coal tar fraction, boiling above 360 °C. It occurs naturally in the tars obtained by the distillation of resinous woods. It crystallizes in large plates, which melt at 98.5 °C and boil at 390 °C. It is readily soluble in warm ether and in hot glacial acetic acid. Sodium and boiling amyl alcohol reduce it to a tetrahydroretene, but if it heated with phosphorus and hydriodic acid to 260 °C, a dodecahydride is formed. Chromic acid oxidizes it to retene quinone, p

'Benzo[a]fluorene (IUPAC name, 11H-benzo[a]fluorene') is a polycyclic aromatic hydrocarbon (PAH). It is currently listed as a Group 3 carcinogen by the IARC.

Hexa-peri-hexabenzocoronene (HBC) is a polycyclic aromatic hydrocarbon with the molecular formula C42H18. It consists of a central coronene molecule, with an additional benzene ring fused between each adjacent pair of rings around the periphery. It is sometimes simply called hexabenzocoronene, however, there are other chemicals that share this less-specific name, such as hexa-cata-hexabenzocoronene.

[[Image:-7-circulene.svg|thumb|upright=0.5|[7]circulene]] A circulene is a macrocyclic arene in which a central polygon is surrounded and fused by benzenoids. Nomenclature within this class of molecules is based on the number of benzene rings surrounding the core, which is equivalent to the size of the central polygon. Examples which have been synthesized include [5]circulene (corannulene), [6]circulene (coronene), [7]circulene, and [12]circulene (kekulene) These compounds belong to a larger class of geodesic polyarenes. Whereas [5]circulene is bowl-shaped and [6]circulene is planar, [7]circul

'Benzo[a]fluoranthene' is an organic compound with the chemical formula C20H12.

medical condition

Benzocyclobutadiene is the simplest polycyclic hydrocarbon, being composed of an aromatic benzene ring fused to an anti-aromatic cyclobutadiene ring. It has chemical formula . Though the benzene ring is stabilized by aromaticity, the cyclobutadiene portion has a destabilizing effect. This results into it being a non-aromatic compound - neither behaving as aromatic nor an antiaromatic one. For this reason, benzocyclobutadiene will readily dimerize or polymerize and it reacts as a dienophile in Diels-Alder reactions.

'Dibenz[a,j]anthracene (also known as benzo[m]tetraphene or 1,2:7,8-dibenzanthracene') is an organic compound with the chemical formula C22H14. It belongs to the class of polycyclic aromatic hydrocarbons (PAHs) and is formed whenever there is incomplete combustion of organic matter. The International Agency for Research on Cancer (IARC) has classified it as possibly carcinogenic to humans, grouped into IARC group 2B.

Dicoronylene is the trivial name for a very large polycyclic aromatic hydrocarbon. It has 15 rings and is a brick-red solid. Its formula is . Dicoronylene sublimes under high vacuum, 0.001 torr, between 250 °C and 300 °C.

9-Methylene-fluorene or dibenzofulvene (DBF) is a polycyclic aromatic hydrocarbon with chemical formula . It is best known as one product from deprotection of the Fmoc group. It can be prepared by treatment of 9-hydroxymethylfluorene with strong base.