Isocetane (2,2,4,4,6,8,8-heptamethylnonane) is a highly branched alkane used as a reference in determining the cetane number of diesel. It has a cetane number of 15.[2] Isocetane replaced 1-methylnaphthalene 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.[3][4]
Names | |
---|---|
IUPAC name
2,2,4,4,6,8,8-Heptamethylnonane[1]
| |
Identifiers | |
3D model (JSmol)
|
|
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.022.280 |
EC Number |
|
MeSH | 2,2,4,4,6,8,8-heptamethylnonane |
PubChem CID
|
|
UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
Properties | |
C16H34 | |
Molar mass | 226.448 g·mol−1 |
Appearance | Colourless liquid |
Odor | Odourless |
Density | 793 mg mL−1 |
Boiling point | 240.1 °C; 464.1 °F; 513.2 K |
Vapor pressure | 130 Pa (at 20 °C) |
Refractive index (nD)
|
1.439 |
Thermochemistry | |
Heat capacity (C)
|
458.80 J K−1 mol−1 |
Hazards | |
Flash point | 96.00 °C (204.80 °F; 369.15 K) |
Related compounds | |
Related alkanes
|
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
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 and so, historically, it has ended up with this name.
References
edit- ^ "2,2,4,4,6,8,8-heptamethylnonane - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification and Related Records. Archived from the original on 30 October 2013. Retrieved 12 March 2012.
- ^ Speight, James G. (2015). Handbook of Petroleum Product Analysis. Hoboken, NJ: Wiley. pp. 158–159. ISBN 978-1-322-95015-0. OCLC 903318141.
- ^ "Cetane number". Archived from the original on 2014-03-12. Retrieved 2007-03-01.
- ^ Jääskeläinen, Hannu (2007). Fuel Property Testing: Ignition Quality. DieselNet Technology Guide (Technical report). ECOpoint Inc. Archived from the original on 2019-06-26. Retrieved 2021-02-24.