Isocetane (2,2,4,4,6,8,8-heptamethylnonane) is a highly branched alkane used as a reference in determining the

cetane number Cetane number (cetane rating) is an indicator of the combustion speed of diesel fuel and compression needed for ignition. It plays a similar role for diesel as octane rating does for gasoline. The CN is an important factor in determining the quali ...

of diesel. It has a cetane number of 15. Isocetane replaced

1-methylnaphthalene 1-Methylnaphthalene is an organic compound with the formula CH3C10H7. It is a colorless liquid. It is isomeric with 2-methylnaphthalene. Reference fuel 1-Methylnaphthalene defines the lower (zero) reference point of cetane number, a measure of d ...

in 1962 as the lower reference for cetane number (1-methylnaphthalene has cetane number zero) owing to the oxidation instability and difficulty of use of 1-methylnaphthalene in the reference engine. Strictly speaking, if the standard meaning of ‘iso’ is followed, the name ''isocetane'' should be reserved for the isomer 2-methylpentadecane. However, 2,2,4,4,6,8,8-heptamethylnonane is by far the most important isomer of

cetane Hexadecane (also called cetane) is an alkane hydrocarbon with the chemical formula C16H34. Hexadecane consists of a chain of 16 carbon atoms, with three hydrogen atoms bonded to the two end carbon atoms, and two hydrogens bonded to each of the 14 ...

and so, historically, it has ended up with this name.

References

{{Organic-compound-stub Alkanes