Pentane, 2,2,4-trimethyl-

• Formula: C₈H₁₈
• Molecular weight: 114.2285
• IUPAC Standard InChI: InChI=1S/C8H18/c1-7(2)6-8(3,4)5/h7H,6H2,1-5H3 Copy

  
• IUPAC Standard InChIKey: NHTMVDHEPJAVLT-UHFFFAOYSA-N Copy
• CAS Registry Number: 540-84-1
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
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• Other names: Isooctane; Isobutyltrimethylmethane; 2,2,4-Trimethylpentane; (CH3)2CHCH2C(CH3)3; Isobutyltrimethylethane; UN 1262
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• Information on this page:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change data
  • Henry's Law data
  • IR Spectrum
  • Gas Chromatography
• Data at other public NIST sites:
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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Constant pressure heat capacity of gas

Reaction thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

 +  =

By formula: C₈H₁₆ + H₂ = C₈H₁₈

 +  =

By formula: C₈H₁₆ + H₂ = C₈H₁₈

=

By formula: C₈H₁₈ = C₈H₁₈

Gas phase ion energetics data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
L - Sharon G. Lias

Data compiled as indicated in comments:
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

Mass spectrum (electron ionization)

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Prosen and Rossini, 1945
Prosen, E.J.; Rossini, F.D., Heats of combustion and formation of the paraffin hydrocarbons at 25° C, J. Res. NBS, 1945, 263-267. [all data]

Scott D.W., 1974
Scott D.W., Chemical Thermodynamic Properties of Hydrocarbons and Related Substances. Properties of the Alkane Hydrocarbons, C1 through C10 in the Ideal Gas State from 0 to 1500 K. U.S. Bureau of Mines, Bulletin 666, 1974. [all data]

Scott D.W., 1974, 2
Scott D.W., Correlation of the chemical thermodynamic properties of alkane hydrocarbons, J. Chem. Phys., 1974, 60, 3144-3165. [all data]

Turner, Nettleton, et al., 1958
Turner, R.B.; Nettleton, J.E.; Perelman, Heats of Hydrogenation. VI. Heats of hydrogenation of some substituted ethylenes, J. Am. Chem. Soc., 1958, 80, 1430-1433. [all data]

Dolliver, Gresham, et al., 1937
Dolliver, M.a.; Gresham, T.L.; Kistiakowsky, G.B.; Vaughan, W.E., Heats of organic reactions. V. Heats of hydrogenation of various hydrocarbons, J. Am. Chem. Soc., 1937, 59, 831-841. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Crawford and Parks, 1936
Crawford, B.L., Jr.; Parks, G.S., The heat of hydrogenation of diisobutylene, J. Am. Chem. Soc., 1936, 58, 373. [all data]

Prosen and Rossini, 1945, 2
Prosen, E.J.; Rossini, F.D., Heats of isomerization of the 18 octanes, J. Res. NBS, 1945, 34, 163-174. [all data]

Al-Joboury and Turner, 1964
Al-Joboury, M.I.; Turner, D.W., Molecular photoelectron spectroscopy. Part II. A summary of ionization potentials, J. Chem. Soc., 1964, 4434. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  Cp,gas	Constant pressure heat capacity of gas
  IE (evaluated)	Recommended ionization energy
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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