Octane is a hydrocarbon and also an alkane with the chemical formula C8H18, and the condensed structural formula CH3(CH2)6CH3. Octane has many structural isomers that differ by the location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (commonly called iso-octane), is used as one of the standard values in the octane rating scale.
Octane is a component of gasoline and petroleum. Under standard temperature and pressure, octane is an odorless, colorless liquid. Like other short-chained alkanes with a low molecular weight, it is volatile, flammable, and toxic. Octane is 1.2 to 2 times more toxic than heptane.[5]
Isomers
N-octane has 23 constitutional isomers. 8 of these isomers have one stereocenter; 3 of them have two stereocenters.
Achiral Isomers:
- 2-Methylheptane
- 4-Methylheptane
- 3-Ethylhexane
- 2,2-Dimethylhexane
- 2,5-Dimethylhexane
- (meso)-3,4-Dimethylhexane
- 3,3-Dimethylhexane
- 3-Ethyl-2-methylpentane
- 3-Ethyl-3-methylpentane
- 2,2,4-Trimethylpentane (i.e. iso-octane)
- 2,3,3-Trimethylpentane
- 2,3,4-Trimethylpentane
- 2,2,3,3-Tetramethylbutane
Chiral Isomers:
- (3R)-3-Methylheptane
- (3S)-3-Methylheptane
- (3R)-2,3-Dimethylhexane
- (3S)-2,3-Dimethylhexane
- (4R)-2,4-Dimethylhexane
- (4S)-2,4-Dimethylhexane
- (3R,4R)-3,4-Dimethylhexane
- (3S,4S)-3,4-Dimethylhexane
- (3R)-2,2,3-Trimethylpentane
- (3S)-2,2,3-Trimethylpentane
Production and Use
In petrochemistry, octanes are not typically differentiated or purified as specific compounds. Octanes are components of particular boiling fractions.[6]
A common route to such fractions is the alkylation reaction between iso-butane and 1-butene, which forms iso-octane.[7]
Octane is commonly used as a solvent in paints and adhesives.
 |
 |
 |
References
- ^ "octane - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification and Related Records. Retrieved 6 January 2012.
- ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0470". National Institute for Occupational Safety and Health (NIOSH).
- ^ Dymond, J. H.; Oye, H. A. (1994). "Viscosity of Selected Liquid n-Alkanes". Journal of Physical and Chemical Reference Data. 23 (1): 41–53. Bibcode:1994JPCRD..23...41D. doi:10.1063/1.555943. ISSN 0047-2689.
- ^ "Octane". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ "1988 OSHA PEL Project - Octane | NIOSH | CDC". www.cdc.gov. 2020-02-27. Retrieved 2024-04-19.
- ^ "Fractionation". www.appliedcontrol.com. Retrieved 2024-04-19.
- ^ Ross, Julian (January 1986). "Ullmann's Encyclopedia of industrial chemistry". Applied Catalysis. 27 (2): 403–404. doi:10.1016/s0166-9834(00)82943-7. ISSN 0166-9834.
External links
- International Chemical Safety Card 0933
- NIOSH Pocket Guide to Chemical Hazards. "#0470". National Institute for Occupational Safety and Health (NIOSH).
- Dr. Duke's Phytochemical and Ethnobotanical Databases, Octane, [1]