Triptane

Not to be confused with triptan, a type of anti-migraine drug, Tryptan, a trade name of tryptophan, or triplane.

Triptane, or 2,2,3-trimethylbutane, is an organic chemical compound with the molecular formula C₇H₁₆ or (H₃C-)₃C-C(-CH₃)₂H. It is therefore an alkane, specifically the most compact and heavily branched of the heptane isomers, the only one with a butane (C₄) backbone.

Triptane

Skeletal formula of triptane Ball-and-Stick model of triptane
Names
Preferred IUPAC name 2,2,3-Trimethylbutane[1]
Identifiers
CAS Number	464-06-2 Y
3D model (JSmol)	Interactive image
Beilstein Reference	1730756
ChemSpider	9649 Y
ECHA InfoCard	100.006.680
EC Number	207-346-3
PubChem CID	10044
UNII	40V943JDGR Y
UN number	1206
CompTox Dashboard (EPA)	DTXSID7060047
InChI InChI=1S/C7H16/c1-6(2)7(3,4)5/h6H,1-5H3 Y Key: ZISSAWUMDACLOM-UHFFFAOYSA-N Y
SMILES CC(C)C(C)(C)C
Properties
Chemical formula	C7H16
Molar mass	100.205 g·mol−1
Appearance	Colorless liquid
Odor	Odorless
Density	0.693 g mL−1
Melting point	−26 to −24 °C; −15 to −11 °F; 247 to 249 K
Boiling point	80.8 to 81.2 °C; 177.3 to 178.1 °F; 353.9 to 354.3 K
Vapor pressure	23.2286 kPa (at 37.7 °C)
Henry's law constant (kH)	4.1 nmol Pa−1 kg−1
Magnetic susceptibility (χ)	−88.36·10−6 cm3/mol
Refractive index (nD)	1.389
Thermochemistry
Heat capacity (C)	213.51 J K−1 mol−1
Std molar entropy (S⦵298)	292.25 J K−1 mol−1
Std enthalpy of formation (ΔfH⦵298)	−238.0 – −235.8 kJ mol−1
Std enthalpy of combustion (ΔcH⦵298)	−4.80449 – −4.80349 MJ mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H302, H305, H315, H336, H400
Precautionary statements	P210, P261, P273, P301+P310, P331
NFPA 704 (fire diamond)	0 3 0
Flash point	−7 °C (19 °F; 266 K)
Autoignition temperature	450 °C (842 °F; 723 K)
Explosive limits	1–7%
Related compounds
Related alkanes	Neopentane 2,2-Dimethylbutane 2,3-Dimethylbutane Tetramethylbutane Tetraethylmethane 2,2,4-Trimethylpentane 2,3,3-Trimethylpentane 2,3,4-Trimethylpentane Tetra-tert-butylmethane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

It was first synthesized in 1922 by Belgian chemists Georges Chavanne (1875–1941) and B. Lejeune, who called it trimethylisopropylmethane.^[2][3]

Due to its high octane rating (112–113 RON, 101 MON^[4][5]) triptane was produced on alkylation units starting from 1943^[6] for use as an anti-knock additive in gasoline. It was extensively researched for this role and received the modern name in the late 1930s at a joint laboratory of NACA, National Bureau of Standards, US Army Air Corps and the Bureau of Aeronautics.^[7]

As of 2011, it was not a significant component of US automobile gasoline, present only in trace amounts (0.05–0.1%).^[8]

See also

• List of gasoline additives