:Triptane
{{distinguish|text=triptan, a type of anti-migraine drug, Tryptan, a trade name of tryptophan, or triplane}}
{{Chembox
| ImageFileL1 = triptane.png
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| ImageSizeL1 = 100
| ImageNameL1 = Skeletal formula of triptane
| ImageFileR1 = 2,2,3trimethylbutane.png
| ImageFileR1_Ref = {{chemboximage|correct|??}}
| ImageSizeR1 = 120
| ImageNameR1 = Ball-and-Stick model of triptane
|Section1={{Chembox Identifiers
| CASNo = 464-06-2
| CASNo_Ref = {{cascite|correct|??}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 40V943JDGR
| PubChem = 10044
| ChemSpiderID = 9649
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| EINECS = 207-346-3
| UNNumber = 1206
| Beilstein = 1730756
| SMILES = CC(C)C(C)(C)C
| StdInChI = 1S/C7H16/c1-6(2)7(3,4)5/h6H,1-5H3
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = ZISSAWUMDACLOM-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
|Section2={{Chembox Properties
| C=7 | H=16
| Appearance = Colorless liquid
| Odor = Odorless
| Density = 0.693 g mL−1
| MeltingPtK = 247 to 249
| BoilingPtK = 353.9 to 354.3
| VaporPressure = 23.2286 kPa (at 37.7 °C)
| HenryConstant = 4.1 nmol Pa−1 kg−1
| RefractIndex = 1.389
| MagSus = −88.36·10−6 cm3/mol
}}
|Section3={{Chembox Thermochemistry
| DeltaHf = −238.0 – −235.8 kJ mol−1
| DeltaHc = −4.80449 – −4.80349 MJ mol−1
| Entropy = 292.25 J K−1 mol−1
| HeatCapacity = 213.51 J K−1 mol−1
}}
|Section4={{Chembox Hazards
| GHSPictograms = {{GHS flame}} {{GHS exclamation mark}} {{GHS health hazard}} {{GHS environment}}
| GHSSignalWord = DANGER
| HPhrases = {{H-phrases|225|302|305|315|336|400}}
| PPhrases = {{P-phrases|210|261|273|301+310|331}}
| NFPA-H = 0
| NFPA-F = 3
| NFPA-R = 0
| FlashPtC = −7
| AutoignitionPtC = 450
| ExploLimits = 1–7%
}}
|Section5={{Chembox Related
| OtherFunction_label = alkanes
| OtherFunction = {{Unbulleted list|Neopentane|2,2-Dimethylbutane|2,3-Dimethylbutane|Tetramethylbutane|Tetraethylmethane|2,2,4-Trimethylpentane|2,3,3-Trimethylpentane|2,3,4-Trimethylpentane|Tetra-tert-butylmethane}}
}}
}}
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.
It was first synthesized in 1922 by Belgian chemists Georges Chavanne (1875–1941) and B. Lejeune, who called it trimethylisopropylmethane.{{Cite journal |last1=Chavanne |first1=G. |last2=Lejeune |first2=B. |date=March 1922 |title=Un nouvel heptane : le triméthylisopropylméthane |url=https://archive.org/details/v31_1922/v31_1922/page/n99/mode/1up |journal=Bulletin de la Société Chimique de Belgique |volume=31 |issue=3 |pages=99–102 |via=Internet Archive}}https://webbook.nist.gov/cgi/cbook.cgi?Source=1922CHA%2FLEJ98
Due to its high octane rating (112–113 RON, 101 MON{{Cite journal |last1=Nash |first1=Connor P. |last2=Dupuis |first2=Daniel P. |last3=Kumar |first3=Anurag |last4=Farberow |first4=Carrie A. |last5=To |first5=Anh T. |last6=Yang |first6=Ce |last7=Wegener |first7=Evan C. |last8=Miller |first8=Jeffrey T. |last9=Unocic |first9=Kinga A. |last10=Christensen |first10=Earl |last11=Hensley |first11=Jesse E. |last12=Schaidle |first12=Joshua A. |last13=Habas |first13=Susan E. |last14=Ruddy |first14=Daniel A. |date=2022-02-01 |title=Catalyst design to direct high-octane gasoline fuel properties for improved engine efficiency |url=https://www.sciencedirect.com/science/article/abs/pii/S0926337321009267 |journal=Applied Catalysis B: Environmental |volume=301 |pages=120801 |doi=10.1016/j.apcatb.2021.120801 |bibcode=2022AppCB.30120801N |osti=1827631 |issn=0926-3373}}{{Cite journal |last1=Perdih |first1=A. |last2=Perdih |first2=F. |date=2006 |title=Chemical Interpretation of Octane Number |journal=Acta Chimica Slovenica|s2cid=55494502 }}) triptane was produced on alkylation units starting from 1943{{Cite web |last=stason.org |first=Stas Bekman: stas (at) |title=10.1 The myth of Triptane |url=https://stason.org/TULARC/vehicles/gasoline-faq/10-1-The-myth-of-Triptane.html |access-date=2024-11-16 |website=stason.org}} 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.{{Cite book |last= |first= |url=https://books.google.com/books?id=9XwiAQAAMAAJ&pg=PA28 |title=Annual Report of the National Advisory Committee for Aeronautics |date=1938 |publisher=U.S. Government Printing Office |pages=28 |language=en}}
As of 2011, it was not a significant component of US automobile gasoline, present only in trace amounts (0.05–0.1%).{{cite web |date=2011 |title=Hydrocarbon Composition of Gasoline Vapor Emissions from Enclosed Fuel Tanks |url=https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100GPED.TXT |website=nepis.epa.gov |publisher=United States Environmental Protection Agency}}