| Naphthalene | |
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| IUPAC name | Naphthalene |
| Other names | Tar Camphor, White Tar, Moth Flakes |
| Identifiers | |
| CAS number | [91-20-3] |
| EINECS number | |
| RTECS number | QJ0525000 |
| SMILES | c1cccc2c1cccc2 |
| Properties | |
| Molecular formula | C10H8 |
| Molar mass | 128. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The EINECS number (for European Inventory of Existing Chemical Substances) is a registry number given to each Chemical substance commercially available in the Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 17052 g/mol |
| Appearance | White solid crystals/flakes, strong odor of coal tar |
| Density | 1. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 14 g/cm³ |
| Melting point |
81. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 2 °C |
| Boiling point |
218 °C |
| Solubility in water | approximately 30 mg/L |
| Hazards | |
| Main hazards | Flammable, sensitizer, possible carcinogen. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Occupational safety and health is a cross-disciplinary area concerned with protecting the Safety, Health and welfare of people engaged in Flammability is the ease with which a substance will ignite causing Fire or Combustion. A sensitiser in Chemoluminescence is a chemical compound capable of Light emission after it has received energy from a molecule which became excited previously The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation Dust can form explosive mixtures with air |
| NFPA 704 |
 2
2
0
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| R-phrases | R22, R40, R50/53 |
| S-phrases | (S2), S36/37, S46, S60, S61 |
| Flash point | 79 - 87 °C |
| Autoignition temperature |
525 °C |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Naphthalene (not to be confused with naphtha), also known as naphthalin, naphthaline, napthene, tar camphor, white tar, albocarbon, or antimite is a crystalline, aromatic, white, solid hydrocarbon, best known as the traditional, primary ingredient of mothballs. An explosive material is a material that either is chemically or otherwise Energetically unstable or produces a sudden expansion of the material usually accompanied Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons i In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. Mothballs are small balls of chemical Pesticide and Deodorant used when storing clothing and other articles susceptible to damage from Mold or Moth It is volatile, forming a flammable vapor, and readily sublimes at room temperature, producing a characteristic odor that is detectable at concentrations as low as 0. A vapor or vapour (see Spelling differences) is a substance in the Gas phase at a Temperature lower than its Critical temperature Sublimation of an element or compound is a transition from the Solid to Gas phase with no intermediate liquid stage 08 ppm by mass. "Parts-per" notation is used especially in Science and Engineering, to denote Ratios (relative proportions in measured quantities particularly [1]
Contents |
History
In 1819–1820, at least two chemists reported a white solid with a pungent odor derived from the distillation of coal tar. In 1821, John Kidd described many of this substance's properties and the means of its production, and proposed the name naphthaline, as it had been derived from a kind of naphtha (a broad term encompassing any volatile, flammable liquid hydrocarbon mixture, including coal tar). John Kidd ( September 10, 1775 &ndash September 7, 1851) was an English Physician, Chemist and geologist Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons i [2] Naphthaline's chemical formula was determined by Michael Faraday in 1826. Michael Faraday, FRS ( September 22 1791 – August 25 1867) was an English The structure of two fused benzene rings was proposed by Emil Erlenmeyer in 1866,[3] and confirmed by Carl Graebe three years later. For his son sometimes known as Emil Jr see Friedrich Gustav Carl Emil Erlenmeyer Richard August Carl Emil Erlenmeyer ( 28 June Carl Gräbe ( February 24, 1841 - January 19, 1927) was a German Chemist from Frankfurt.
Structure and reactivity
A naphthalene molecule is composed of two fused benzene rings. (In organic chemistry, rings are fused if they share two or more atoms. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation ) Accordingly, naphthalene is classified as a benzenoid polycyclic aromatic hydrocarbon (PAH). Polycyclic aromatic hydrocarbons ( PAH s are Chemical compounds that consist of fused Aromatic rings and do not contain Heteroatoms or There are two sets of equivalent hydrogens: the alpha positions are positions 1, 4, 5, and 8 on the drawing below, and the beta positions are positions 2, 3, 6, and 7.
Unlike highly-symmetrical aromatics, such as benzene, the carbon-carbon bonds in naphthalene are not of the same length. Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 The bonds C1–C2, C3–C4, C5–C6 and C7–C8 are about 1. 36 Å (136 pm) in length, whereas the other carbon-carbon bonds are about 1. 42 Å (142 pm) long. This has been verified by x-ray diffraction, and is consistent with the valence bond model of bonding in napthalene which involves three resonance structures (as shown below); while the bonds C1–C2, C3–C4, C5–C6 and C7–C8 are double in two of the three structures, the others are double in only one. X-ray scattering techniques are a family of non-destructive analytical techniques which reveal information about the crystallographic structure chemical composition In Chemistry, valence bond theory explains the nature of a Chemical bond in a Molecule in terms of atomic valencies. Resonance in Chemistry is a theory used to represent and model certain types of non-classical Molecular structures Resonance is a key component
Like benzene, naphthalene can undergo electrophilic aromatic substitution. Electrophilic aromatic substitution or EAS is an Organic reaction in which an atom usually Hydrogen, appended to an aromatic system is replaced For many electrophilic aromatic substitution reactions, naphthalene is more reactive than benzene, reacting under milder conditions than does benzene. For example, whereas both benzene and naphthalene react with chlorine in the presence of a ferric chloride or aluminium chloride catalyst, naphthalene and chlorine can react to form 1-chloronaphthalene even without a catalyst. Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and Iron chloride redirects here For Iron(II chloride see Iron(II chloride. Aluminium chloride (AlCl3 is a compound of Aluminium and Chlorine. Similarly, while both benzene and naphthalene can be alkylated using Friedel-Crafts reactions, naphthalene can also be alkylated by reaction with alkenes or alcohols, with sulfuric or phosphoric acid as the catalyst. The Friedel-Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877. In Organic chemistry, an alkene, olefin, or olefine is an unsaturated Chemical compound containing at least one Carbon In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. Phosphoric acid, also known as orthophosphoric acid or phosphoric(V acid, is a mineral (inorganic acid having the Chemical formula
Two isomers are possible for mono-substituted naphthalenes, corresponding to substitution at an alpha or beta position. This article is about the chemical concept For "isomerism" of atomic nuclei see Nuclear isomer. Usually, electrophiles attack at the alpha position. The selectivity for alpha over beta substitution can be rationalized in terms of the resonance structures of the intermediate: for the alpha substitution intermediate, seven resonance structures can be drawn, of which four preserve an aromatic ring. For beta substitution, the intermediate has only six resonance structures, and only two of these are aromatic. Sulfonation, however, gives a mixture of the "alpha" product 1-naphthalenesulfonic acid and the "beta" product 2-naphthalenesulfonic acid, with the ratio dependent on reaction conditions. The 1-isomer forming predominantly at 25OC, and the 2-isomer at 160OC.
Naphthalene can be hydrogenated under high pressure with metal catalysts to give 1,2,3,4-tetrahydronaphthalene or tetralin (C10H14). Hydrogenation is the Chemical reaction that results in addition of Hydrogen (H2 Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Tetralin (1234-Tetrahydronaphthalene is a Hydrocarbon having the chemical formula C10H12 Further hydrogenation yields decahydronaphthalene or decalin (C10H18). Decahydronaphthalene (also known as decalin, or as bicyclodecane) a Bicyclic Organic compound, is an industrial Solvent. Oxidation with chromate or permanganate, or catalytic oxidation with O2 and a vanadium catalyst, gives phthalic acid. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Chromates and dichromates are Salts of Chromic acid and dichromic acid respectively Vanadium (vəˈneɪdiəm is a Chemical element that has the symbol V and Atomic number 23 Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Phthalic acid ( IUPAC Systematic name: benzene-12-dicarboxylic acid) is an Aromatic Dicarboxylic acid, with formula C6H4(COOH2
Production
Most naphthalene is derived from coal tar. Coal tar is a brown or black liquid of high Viscosity, which smells of Naphthalene and Aromatic hydrocarbons Coal tar is among the by-products when coal From the 1960s until the 1990s, significant amounts of naphthalene were also produced from heavy petroleum fractions during petroleum refining, but today petroleum-derived naphthalene represents only a minor component of naphthalene production. An oil refinery is an industrial Process plant where Crude oil is processed and refined into more useful Petroleum products, such as Gasoline
Naphthalene is the most abundant single component of coal tar. While the composition of coal tar varies with the coal from which it is produced, typical coal tar is about 10% naphthalene by weight. In industrial practice, distillation of coal tar yields an oil containing about 50% naphthalene, along with a variety of other aromatic compounds. Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture This oil, after being washed with aqueous sodium hydroxide to remove acidic components (chiefly various phenols), and with sulfuric acid to remove basic components, is fractionally distilled to isolate naphthalene. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Phenol, is a toxic colourless Crystalline Solid with a sweet tarry odor commonly referred to as a "hospital smell" Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and Fractional distillation is the separation of a mixture into its component parts or fractions such as in separating Chemical compounds by their Boiling point by heating The crude naphthalene resulting from this process is about 95% naphthalene by weight, often referred to as 780C (melting point). The chief impurities are the sulfur-containing aromatic compound benzothiophene (<2%), indane (0. Benzothiophene is an Aromatic Organic compound with a molecular formula C8H6S and an odor similar to Naphthalene (mothballs Indane is a Hydrocarbon petrochemical compound Derivatives include compounds such as 1-methyl-indane and 2-methyl-indane (where one methyl group is attached to the five 2%), indene (<2%), and methylnapthalene (<2%). Indene is a Flammable polycyclic Hydrocarbon with Chemical formula C9H8 Petroleum-derived naphthalene is usually purer than that derived from coal tar. Where required, crude naphthalene can be further purified by recrystallization from any of a variety of solvents, resulting in 99% naphthalene by weight, referred to as 800C (melting point). Recrystallization (see also Crystallization) is a physical process that has meanings in Chemistry, Metallurgy and Geology.
In North America, coal tar producers are Koppers Inc. Koppers is a global chemical and materials company based in Downtown Pittsburgh, Pennsylvania, United States in an Art-deco 1920's and Recochem Inc. , and petroleum-derived producer is Advanced Aromatics, L. P. .
Incidence in nature
Trace amounts of naphthalene are produced by magnolias and specific types of deer. Magnolia is a large Genus of about 210 Flowering plant Species in the subclass Magnolioideae of the family A deer is a Ruminant Mammal belonging to the family Cervidae. Naphthalene has also been found in the Formosan subterranean termite, possibly as a repellant against "ants, poisonous fungi and nematode worms. The Formosan subterranean termite ( Coptotermes formosanus) is an invasive species of Termite. " [1]
Uses
Naphthalene's most familiar use is as a household fumigant, such as in mothballs (although 1,4-dichlorobenzene (or p-dichlorobenzene) is now more widely used). Fumigation is a method of Pest control that completely fills an area with gaseous Pesticides to suffocate or poison the pests within Mothballs are small balls of chemical Pesticide and Deodorant used when storing clothing and other articles susceptible to damage from Mold or Moth In a sealed container containing naphthalene pellets, naphthalene vapors build up to levels toxic to both the adult and larval forms of many moths that attack textiles. A moth is an Insect closely related to the Butterfly, both being of the order Lepidoptera. Other fumigant uses of naphthalene include use in soil as a fumigant pesticide, in attic spaces to repel animals and insects, and in museum storage-drawers and cupboards to protect the contents from attack by insect pests. An attic is a space found directly below the pitched Roof of a house or other building (also called garret, Loft or
It is used in pyrotechnic special effects such as the generation of black smoke and simulated explosions.
It is used to create artificial pores in the manufacture of high-porosity grinding wheels.
In the past, naphthalene was administered orally to kill parasitic worms in livestock.
Naphthalene vapour can also slow the onset of rust, such as the use of moth balls in a tool box. Rust is a general term for a series of Iron oxides, usually red oxides formed by the reaction of Iron with Oxygen in the presence of water or air
Naphthalene and its alkyl homologs are the major constituents of creosote. A homolog in Chemistry refers to a Chemical compound from a series of compounds that differ only in the number of repeated structural units. Creosote is the name used for a variety of products including wood creosote and coal tar creosote.
Use as a chemical intermediate
Larger volumes of naphthalene are used as a chemical intermediate to produce other chemicals. The single largest use of naphthalene is the industrial production of phthalic anhydride (although more phthalic anhydride is made from o-xylene than from naphthalene). Phthalic anhydride is the Organic compound with the formula C6H4(CO2O o -Xylene is an Aromatic Hydrocarbon, based on Benzene with two Methyl Substituents bonded to adjacent carbon atoms Other naphthalene-derived chemicals include alkyl naphthalene sulfonate surfactants, and the insecticide 1-naphthyl-N-methylcarbamate (carbaryl). Surfactants are wetting agents that lower the Surface tension of a liquid allowing easier spreading and lower the Interfacial tension between two liquids An insecticide is a Pesticide used against Insects in all developmental forms Carbaryl (1-naphthyl methylcarbamate is a chemical in the Carbamate family used chiefly as an Insecticide. Naphthalenes substituted with combinations of strongly electron-donating functional groups, such as alcohols and amines, and strongly electron-withdrawing groups, especially sulfonic acids, are intermediates in the preparation of many synthetic dyes. In Organic chemistry, functional groups are specific groups of Atoms within Molecules that are responsible for the characteristic Chemical reactions In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. Sulfonic acid is an unstable Acid with the formula H-S(=O2-OH A dye can generally be described as a Colored substance that has an affinity to the substrate to which it is being applied The hydrogenated naphthalenes tetrahydronaphthalene (tetralin) and decahydronaphthalene (decalin) are used as low-volatility solvents. Tetralin (1234-Tetrahydronaphthalene is a Hydrocarbon having the chemical formula C10H12 Decahydronaphthalene (also known as decalin, or as bicyclodecane) a Bicyclic Organic compound, is an industrial Solvent. A solvent is a liquid or gas that dissolves a solid liquid or gaseous Solute, resulting in a Solution.
Naphthalene sulfonic acids are used in the manufacture of naphthalene sulfonate polymer plasticizers which are used to produce concrete and plasterboard (wallboard or drywall). Plasticizers are additives that increase the Plasticity or Fluidity of the material to which they are added these include plastics cement concrete wallboard and Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag For the musical group "Drywall" see Drywall (musical project Drywall is a common manufactured Building material For the musical group "Drywall" see Drywall (musical project Drywall is a common manufactured Building material For the musical group "Drywall" see Drywall (musical project Drywall is a common manufactured Building material They are also used as dispersants in synthetic and natural rubbers, and as tanning agents in leather industries. A dispersant or Plasticizer is a liquid or gas added to a mixture to promote dispersion or to maintain dispersed particles in suspension Tanning is the process of converting Putrescible skin into non-putrescible Leather, usually with Tannin, an Acidic Chemical compound Naphthalene sulfonate polymers are produced by reacting naphthalene with sulfuric acid and polymerizing this with formaldehyde, followed by neutralization with sodium hydroxide.
Naphthalene is also used in the synthesis of 2-naphthol, and of miscellaneous chemicals and pharmaceuticals. beta-Naphtholsvg|thumb|150px|β-Naphthol]] Naphthol, or hydroxynaphthalene or naphthalenol is either of two colorless crystalline solids with the formula C10H7OH
Health effects
Exposure to large amounts of naphthalene may damage or destroy red blood cells. Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood Humans, particularly children, have developed this condition, known as hemolytic anemia, after ingesting mothballs or deodorant blocks containing naphthalene. Hemolytic anemia is Anemia due to Hemolysis, the abnormal breakdown of Red blood cells (RBCs either in the Blood vessels (intravascular hemolysis Symptoms include fatigue, lack of appetite, restlessness, and pale skin. The skin is the outer covering of living tissue of an animal (or plant Exposure to large amounts of naphthalene may cause nausea, vomiting, diarrhea, blood in the urine, and jaundice (yellow coloration of the skin). Nausea ( Latin: Nausea, Greek:, " Sea-sickness " also called wamble) is the sensation of unease and discomfort In Medicine, diarrhea, also spelled diarrhoea (see spelling differences) is frequent loose or liquid Bowel movements Acute diarrhea Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells such as nutrients and oxygen—and transports Waste products Urine is a liquid waste product of the body secreted by the Kidneys by a process of filtration from Blood and Excreted through the Urethra. Jaundice, also known as icterus (attributive adjective "icteric" is yellowish discoloration of the Skin, sclerae (whites of the eyes
When the U. S. National Toxicology Program exposed male and female rats and mice to naphthalene vapors on weekdays for two years,[4] male and female rats exhibited: evidence of carcinogenic activity, based on increased incidences of adenoma and neuroblastoma of the nose, female mice exhibited some evidence of carcinogenic activity, based on increased incidences of alveolar and bronchiolar adenomas of the lung, and male mice exhibited no evidence of carcinogenic activity.
The International Agency for Research on Cancer (IARC)[5] classifies naphthalene as possibly carcinogenic to humans [Group 2B]. The IARC also points out that acute exposure causes cataracts in humans, rats, rabbits, and mice, and that hemolytic anemia, described above, can occur in children and infants after oral or inhalation exposure or after maternal exposure during pregnancy.
Over 400 million people have an inherited condition called glucose-6-phosphate dehydrogenase deficiency. Glucose-6-phosphate dehydrogenase deficiency is an X-linked recessive Hereditary disease characterised by abnormally low levels of Glucose-6-phosphate Exposure to naphthalene is more harmful for these people and may cause hemolytic anemia at lower doses.
See also
- Decahydronaphthalene (the fully saturated analog of naphthalene)
- Naphthol
- Classic naphthalene synthesis: the Wagner-Jauregg reaction
References
- ^ Amoore J E and Hautala E (1983). Decahydronaphthalene (also known as decalin, or as bicyclodecane) a Bicyclic Organic compound, is an industrial Solvent. beta-Naphtholsvg|thumb|150px|β-Naphthol]] Naphthol, or hydroxynaphthalene or naphthalenol is either of two colorless crystalline solids with the formula C10H7OH The Wagner-Jauregg reaction is a classic Organic reaction in Organic chemistry, named after Theodor Wagner-Jauregg, describing the Diels-Alder reaction "Odor as an aid to chemical safety: Odor thresholds compared with threshold limit values and volatiles for 214 industrial chemicals in air and water dilution". J Appl Toxicology 3 (6): 272-290.
- ^ John Kidd (1821). "Observations on Naphthaline, a peculiar substance resembling a concrete essential oil, which is apparently produced during the decomposition of coal tar, by exposure to a red heat". Philosophical Transactions 111: 209-221.
- ^ Emil Erlenmeyer (1866). "Studien über die s. g. aromatischen Säuren". Annalen der Chemie und Pharmacie 137 (3): 327 - 359. Official title Annalen der Chemie, 1832–1839 Annalen der Chemie und Pharmacie, 1840–1872 (ISSN 0075-4617 CODEN JLACBF doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ NTP Technical Reports 410 and 500. NTP Technical Reports 410 and 500, available from NTP: Long-Term Abstracts & Reports. Retrieved on March 6, 2005.
- ^ IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Monographs on the Evaluation of Carcinogenic Risks to Humans, Some Traditional Herbal Medicines, Some Mycotoxins, Naphthalene and Styrene, Vol. 82 (2002) (p. 367). Retrieved on March 9, 2005.
External links
- National Pesticide Information Center - Mothballs Case Profile
- Naphthalene - EPA Air Toxics Web Site
- Naphthalene (PIM 363) - mostly on toxicity of naphthalene
- Koppers Inc. [2]
- Recochem Inc. [3]
- Advanced Aromatics, L. P. [4]
Dictionary
naphthalene
-noun
- A white crystalline hydrocarbon manufactured from coal tar; used in mothballs.
- (organic chemistry) An aromatic bicyclic hydrocarbon, C10H8; an acene containing two fused benzene rings.
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