See Also

Toluene

Toluene, also known as methylbenzene or phenylmethane is a clear, water Water

Water is a taste [i]less, odor [i]less substance that is essential to all known forms of life [i] and i ... 

-insoluble liquid with the typical smell of paint thinners, reminiscent of the sweet smell of the related compound benzene Benzene

Benzene, also known as benzol, is an organic [i] chemical compound [i] with the ... 

. It is an aromatic hydrocarbon Aromatic hydrocarbon

An aromatic hydrocarbon or arene is a hydrocarbon [i], the molecular structure [i] of which inco ... 

 that is widely used as an industrial feedstock and as a solvent.

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Toluene
General
Systematic name IUPAC nomenclature

IUPAC nomenclature is a system of naming chemical compound [i]s and of describing the science of chemistry [i] ... 

toluene
Other names methylbenzene
phenylmethane
toluol
Molecular formula Chemical formula

A chemical formula is a concise way of expressing information about the atom [i]s that constitute a par ... 

C7H8
SMILES Simplified molecular input line entry specification

The simplified molecular input line entry specification or SMILES is a specification for unambiguo... 

Cc1ccccc1
Molar mass 92.14 g/mol
Appearance Clear, colourless liquid
CAS number [108-88-3]
Properties
Density and phase 0.8669 g/cm3, liquid
Solubility in water Water

Water is a taste [i]less, odor [i]less substance that is essential to all known forms of life [i] and i ... 

0.053 g/100 mL
In ethanol Ethanol

This article is about the chemical compound.... 

,
acetone Acetone

In chemistry [i], acetone is the simplest representative of the ketone [i]s.
... 

, hexane Hexane

Hexane is an alkane [i] hydrocarbon [i] with the chemical formula [i] CH3(CH2)4CH3. ... 

,
dichloromethane Dichloromethane

Dichloromethane or methylene chloride is the chemical compound [i] with the formula CH2Cl2. ... 

Fully miscible
Melting point -93 °C /
Boiling point 110.6 °C / 231.08°F
Critical temperature 320 °C / 608°F
Viscosity Viscosity

Viscosity is a measure of the resistance of a fluid [i] to deform under shear stress [i]. ... 

0.590 cP at 20°C/ 68°F
Dipole moment Dipole

Definition

In physics, there are two kinds of dipoles = double and polos = pivot).... 

0.36 D
Hazards
MSDS Material safety data sheet

A material safety data sheet is a form containing data regarding the properties of a particular substanc... 

External MSDS
Main hazards highly flammable
NFPA 704 NFPA 704

NFPA 704 is a standard maintained by the U.S. [i] National Fire Protection Association [i] ... 

Flash point 4 °C/ 39.2 °F
R-phrases ,
S-phrases , , ,
RTECS number XS5250000
Supplementary data page Toluene

Toluene, also known as methylbenzene or phenylmethane is a clear, water [i]-insoluble ... 

Structure & properties n, er, etc.
Thermodynamic data Phase behaviour
Solid, liquid, gas
Spectral data UV Ultraviolet-visible spectroscopy

Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry involves the spectroscopy [i] ... 

, IR Infrared spectroscopy

Infrared spectroscopy is the subset of spectroscopy [i] that deals with the Infrared [i] part of the electromagnetic spectrum [i] ... 

, NMR NMR spectroscopy

Nuclear Magnetic Resonance Spectroscopy most commonly known as NMR Spectroscopy is the name given ... 

, MS Mass spectrometry

Mass spectrometry is an analytical technique used to measure the mass-to-charge ratio [i] of ion [i]s. ... 

Related compounds
Related aromatic
hydrocarbons
Aromatic hydrocarbon

An aromatic hydrocarbon or arene is a hydrocarbon [i], the molecular structure [i] of which inco ... 

benzene Benzene

Benzene, also known as benzol, is an organic [i] chemical compound [i] with the ... 


xylene Xylene

The term xylenes refers to a group of 3 benzene [i] derivatives which encompasses ortho-, meta-, ... 


naphthalene Naphthalene

Naphthalene is a crystalline, aromatic [i], white, solid hydrocarbon [i], best known as the ... 

Related compounds methylcyclohexane
Except where noted otherwise, data are given for
materials in their standard state Standard state

In chemistry [i], the standard state of a material is its state [i] at 1 bar [i]. ... 



Toluene, also known as methylbenzene or phenylmethane is a clear, water Water

Water is a taste [i]less, odor [i]less substance that is essential to all known forms of life [i] and i ... 

-insoluble liquid with the typical smell of paint thinners, reminiscent of the sweet smell of the related compound benzene Benzene

Benzene, also known as benzol, is an organic [i] chemical compound [i] with the ... 

. It is an aromatic hydrocarbon Aromatic hydrocarbon

An aromatic hydrocarbon or arene is a hydrocarbon [i], the molecular structure [i] of which inco ... 

 that is widely used as an industrial feedstock and as a solvent.

History

The name toluene was derived from the older name toluol that refers to tolu balsam, an aromatic extract from the tropical American tree Myroxylon balsamum, from which it was first isolated. It was originally named by Jöns Jakob Berzelius Jöns Jakob Berzelius

Jns Jakob Berzelius was a Swedish [i] chemist. ... 

.

Chemical properties

Toluene reacts as a normal aromatic hydrocarbon Aromatic hydrocarbon

An aromatic hydrocarbon or arene is a hydrocarbon [i], the molecular structure [i] of which inco ... 

 towards electrophilic aromatic substitution Electrophilic aromatic substitution

Electrophilic aromatic substitution or EAS is an organic reaction [i] in which an atom, usually Hydrogen [i] ... 

. The methyl group makes it around 25 times more reactive than benzene Benzene

Benzene, also known as benzol, is an organic [i] chemical compound [i] with the ... 

 in such reactions. It undergoes smooth sulfonation Sulfonic acid

Sulfonic acid is an hypothetical acid [i] with formula H-S(=O)2-OH. ... 

 to give p-toluenesulfonic acid P-Toluenesulfonic acid

Toluenesulfonic acid, or tosic acid,, is the organic compound [i] with the formula CH3C6H4SO3H. ... 

, and chlorination by Cl2 in the presence of FeCl3 to give ortho and para isomer Isomer

In chemistry [i], isomers are molecule [i]s with the same chemical formula [i] and often with the same k ... 

s of chlorotoluene Benzyl chloride

Benzyl chloride, or a-chlorotoluene, is an organic compound [i] consisting of a benzene [i] ring substit ... 

. It undergoes nitration Nitration

Nitration is a general chemical process [i] for the introduction of a nitro [i] group in a chemical compound [i]... 

 to give ortho and para nitrotoluene isomers, but if heated it can give dinitrotoluene and ultimately the explosive trinitrotoluene Trinitrotoluene

Trinitrotoluene is an explosive [i].... 

 .

With other reagents the methyl side chain in toluene may react, undergoing oxidation. Reaction with potassium permanganate Potassium permanganate

Potassium permanganate is the chemical compound [i] K [i]Mn [i]O [i]4. ... 

 leads to benzoic acid Benzoic acid

Benzoic acid, C6H5COOH, is a colourless crystalline solid and the simplest [[aromatic compound|aromatic]... 

, whereas reaction with chromyl chloride Chromyl chloride

Chromyl chloride is a chemical compound with the formula CrO2Cl2.... 

 leads to benzaldehyde Benzaldehyde

Benzaldehyde is a chemical compound consisting of a benzene [i] ring with an aldehyde [i] substituent. ... 

 . Halogenation Halogenation

Halogenation is a chemical reaction [i] that replaces a hydrogen [i] atom with a halogen [i] atom. ... 

 can be performed under free radical Radical (chemistry)

In chemistry [i], radicals are atom [i]ic or molecular [i] species with unpaired electron [i]s ... 

 conditions. For example, N-bromosuccinimide N-Bromosuccinimide

N-Bromosuccinimide or NBS is a chemical reagent [i] which is used in radical substitution [i] and ... 

  heated with toluene in the presence of AIBN Azobisisobutylonitrile

Azobisisobutyronitrile is a toxic [i] compound often used as a foamer in plastics [i] and rubber [i] and ... 

 leads to benzyl bromide Benzyl bromide

Benzyl bromide, or a-bromotoluene, is an organic compound [i] consisting of a benzene [i] ring substitut... 

.

Catalytic hydrogenation of toluene to methylcyclohexane requires a high pressure of hydrogen Hydrogen

|-
| Triple point [i] || 13.8033 K, 7.042 kPa
... 

 to go to completion, because of the stability of the aromatic system.

Preparation

Toluene occurs naturally at low levels in crude oil Petroleum

Petroleum or crude oil is a black, dark brown or greenish liquid [i] found in porous rock formati ... 

 and is usually produced in the processes of making gasoline Gasoline

Gasoline, also called petrol, is a petroleum [i]-derived liquid [i] mixture consisting primarily o ... 

 via a catalytic reformer, in an ethylene Ethylene

Ethylene is the simplest alkene [i] hydrocarbon [i], consisting of four hydrogen [i] atom [i]s and two... 

 cracker or making coke from coal Coal

Coal is a fossil fuel [i] extracted from the ground by underground mining or open-pit mining . ... 

. Final separation takes place in a BTX plant.

Uses

Toluene is a common solvent, able to dissolve: paint Paint

Paint is the general term for a family of products used to protect and add color [i] to an object or sur ... 

s, paint thinners, many chemical reactant Chemical reaction

A chemical reaction is a process that results in the interconversion of chemical substance [i]s . ... 

s, rubber Rubber

Rubber is an elastic hydrocarbon [i] polymer [i] which occurs as a milky emulsion [i] in the sap of se ... 

, printing Printing

Printing is a process for production of text [i]s and , typically with ink [i] on paper [i] using a printing press [i] ... 

 ink, adhesive Adhesive

An adhesive is a compound that adheres [i] or bonds two items together. ... 

s , lacquer Lacquer

In a general sense, lacquer is a clear or coloured coating, that dries by solvent evaporation only and t... 

s, leather tanners Tanning

Tanning is the process of conversion of putrescible [i] skin into non putrescible leather.This is common ... 

, and disinfectants. It can also be used as a fullerene Fullerene

The fullerenes are a recently-discovered family of carbon [i] allotropes [i] named... 

 indicator, and is a raw material for toluene diisocyanate Isocyanate

Isocyanate is the functional group [i] of atoms –N=C=O , not to be confused with the cyanate [i] f ... 

 , phenol Phenol

Phenol, also known under an older name of carbolic acid, is a colorless crystal [i]line solid [i] ... 

 and TNT Trinitrotoluene

Trinitrotoluene is an explosive [i].... 

. Toluene can be used as an octane booster Octane rating

The octane rating is a measure of the autoignition [i] resistance of gasoline [i] and other fuels used i ... 

 in gasoline Gasoline

Gasoline, also called petrol, is a petroleum [i]-derived liquid [i] mixture consisting primarily o ... 

 fuels used in internal combustion engine Internal combustion engine

The internal combustion engine is a heat engine [i] in which the burning of a fuel [i] occurs ... 

s. Toluene at 84% by volume, fueled all the turbo Formula 1 teams in the 1980s. Small 1.5L turbo engines were known to operate at 5 bar boost in qualifying and 4 bars while racing. More than 1500bhp from 1.5L engines was possible. For proper atomization, the Toluene fuel blend was preheated. Industrial uses of toluene include dealkylation to benzene and disproportionation to a mixture of benzene and xylene Xylene

The term xylenes refers to a group of 3 benzene [i] derivatives which encompasses ortho-, meta-, ... 

.

Toxicology and metabolism

Inhalation of toluene fumes can be intoxicating, but in larger doses nausea-inducing. Chronic or frequent inhalation Inhalant

Inhalants are a chemically diverse group of psychoactive [i] substances composed of or ... 

 of toluene over long time periods leads to irreversible brain damage. Toluene may enter the human system not only through vapour inhalation from the liquid evaporation, but also following soil contamination Soil contamination

Soil contamination is the presence of man made chemicals or other alteration to the natural soil environ... 

 events, where human contact with soil, ingestion of contaminated groundwater or soil vapour off-gassing can occur.

The toxicity of toluene can be explained mostly by its metabolism. As toluene has very low water solubility, it cannot exit the body via the normal routes . It must be metabolized in order to be excreted. The methyl group of toluene is more easily oxidized by cytochrome P450 Cytochrome P450 oxidase

Cytochrome P450 oxidase is a generic term for a large number of related, but distinct, oxidative [i] ... 

 than the benzene ring. Therefore, in the metabolism of toluene, 95% is oxidized to become benzyl alcohol Benzyl alcohol

Benzyl alcohol, also known as phenylmethanol, or phenylcarbinol, is a clear, colorless liqui... 

. The toxic metabolites are created by the remaining 5% that are ring oxidized to epoxides. Most of the epoxides become glutathione Glutathione

Glutathione, whose IUPAC [i] name is 2-amino-5--5-oxopentanoic acid, is ?-glutamylcysteinylglycine, a tripeptide [i] ... 

 conjugated. However, the remainder will severely damage cells.



Toluene is mainly excreted as benzoic acid Benzoic acid

Benzoic acid, C6H5COOH, is a colourless crystalline solid and the simplest [[aromatic compound|aromatic]... 

 and hippuric acid Hippuric acid

Hippuric acid, benzoyl glycocoll or benzoyl amidoacetic acid, C9H9NO3 or C6H5CONHCH2CO2H, is an organic ... 

, both formed by further metabolic oxidation of benzyl alcohol.


Behavioural Effects of Long Term Exposure

Serious adverse behavioural effects are often associated with toluene abuse related to the deliberate inhalation of solvents.4 Long term toluene exposure is often associated with effects such as: psychoorganic syndrome;5 visual evoked potential abnormality;5 toxic polyneuropathy, cerebellar Cerebellum

The cerebellum is a region of the brain [i] that plays an important role in the integration of sensory perception [i] ... 

, cognitive Cognition

The term cognition is used in several loosely related ways to refer to a facility for the human-like pro... 

, and pyramidal dysfunctions;5 optic atrophy; and brain lesions.4

Toluene causes postural tremors by increasing extracellular concentrations of ?-aminobutyric acid  within the cerebellar cortex Cerebellum

The cerebellum is a region of the brain [i] that plays an important role in the integration of sensory perception [i] ... 

.4 Treatment with GABA agonists such as, benzodiazepines Benzodiazepine

The benzodiazepines are a class of drugs [i] with sedative [i], hypnotic [i], anxiolytic [i] ... 

 provide some relief from toluene induced tremor and ataxia.4 An alternative to drug treatment is vim thalamotomy.4 The tremors associated with toluene misuse do not seem to be a transient symptom, but an irreversible and progressive symptom which continues after solvent abuse has been discontinued.4

There is some evidence that low level toluene exposure may cause disruption in the differentiation of astrocyte precursor cells.6 This does not appear to be a major hazard to adults; however, exposure of pregnant women to toluene during critical stages of fetal development could cause serious disruption to neuronal development.6

See also

  • Soil contamination Soil contamination

    Soil contamination is the presence of man made chemicals or other alteration to the natural soil environ... 

  • Water pollution Water pollution

    Water pollution is a large set of adverse effects upon water bodies caused by human activities.... 



External links



References

  1. B. S. Furnell et al., Vogel's Textbook of Practical Organic Chemistry, 5th edition, Longman/Wiley, New York, 1989.
  2. L. G. Wade, Organic Chemistry, 5th ed., p. 871, Prentice Hall, Upper Saddle RIver, New Jersey, 2003.
  3. J. March, Advanced Organic Chemistry, 4th ed., p. 723, Wiley, New York, 1992.
  4. Miyagi, Y., Shima, F., Ishido, K. et al. Tremor induced by toluene misuse successfully treated by a Vim thalamotomy. Journal of Neurology Neurosurgery and Psychiatry 66:794-6, .
  5. Urban, P., Lukáš, E., Pelclová, D. et al. Neurological and Neurophysiological Follow-up on Workers With Severe Chronic Exposure to Toluene. Neurotoxicity P25:s130, .
  6. Yamaguchi, H., Kidachi, Y. and Ryoyama, K. Toluene at Environmentally Relevant Low Levels Disrupts Differentiation of Astrocyte Precursor Cells. Archives of Environmental Health 57:232-8, .