Also found in: Dictionary, Wikipedia.


(organic chemistry)
(CH3)2CHCH2C(CH3)3 Flammable, colorless liquid boiling at 99°C; slightly soluble in alcohol and ether, insoluble in water; used in motor fuels and as a chemical intermediate.



2,2,4-trimethylpentane, the saturated aliphatic hydrocarbon C(CH3)3—CCH2—CH(CH3)2.

Isooctane is a transparent colorless liquid with a gasoline odor. Melting point, - 107.38°C; boiling point, 99.24°C; density, 0.69192 g/cm3 (20°C); nD20, 1.39145; heat of combustion, 5.463 megajoules per mole, or 1,305.29 kilocalories per mole (25°C; p = const); heat of vaporization, 307.63 joules per g, or 73.50 calories per g (25°C). Isooctane is insoluble in water but soluble in ordinary organic solvents. It forms azeotropes (for example, with benzene, methanol, and ethanol). The knock rating of isooctane is assigned an octane number of 100.

Straight-run gasolines contain small amounts of isooctane along with other octane isomers. Industrially, isooctane is made by hydrogenating diisobutylene over a catalyst (for example, copper-chromium) or by alkylating isobutane with isobutylene in the presence of concentrated H2S04, A1C13, BF3, or other catalysts. Isooctane is used (as an additive) in making aviation gasolines, which must have excellent antiknock properties.

References in periodicals archive ?
Biofuels company Gevo Inc (NasdaqCM:GEVO) reported on Tuesday the launch of a Letter of Intent (LOI) with HCS Holding GmbH (HCS) for the supply of isooctane.
Overall migration tests are carried out on PHB/CNC films using ethanol (10% v/v) and isooctane as simulants at incubation temperature 20 and 40[degrees]C, respectively, for a period of 2 and 10 days respectively, in order to determine the CNC and PHB fractions that might migrate when the these films are brought in contact with food materials (Fig.
One ml isooctane was added to the extracts that were again concentrated to 0.
Samples were injection molded into discs and sealed over a cup half-filled with CE10 (45% isooctane, 45% toluene, and 10% ethanol) or CM15A (42.
Heretofore, avgas has been composed of what refiners call aviation alkylate, a blend of branched-chain hydrocarbons consisting of isomers of isooctane.
The collaboration is aimed at the development of isobutene-derived isooctane, a high performance biofuel for petrol engines.
Light molecules such as propane, butane or pentane are reacted with isobutane in the presence of a catalyst (either hydrofluoric or sulphuric acid) to produce isoheptane (iC7), isooctane (iC8) or isononane (iC9) respectively which are prime blending components for motor gasoline.
The decanted extract was evaporated at 40[degrees] in the rotary evaporator under reduced pressure to near dryness, dissolved in isooctane (1ml) for silica clean up.
The materials include jet fuel, isooctane for gasoline, isooctene and paraxylene for polyethylene terephthalate.
using isooctane, which arbitrarily received a rating of 100.