1,2-Butadiene, 3-methyl-

• Formula: C₅H₈
• Molecular weight: 68.1170
• IUPAC Standard InChI: InChI=1S/C5H8/c1-4-5(2)3/h1H2,2-3H3 Copy

  
• IUPAC Standard InChIKey: PAKGDPSCXSUALC-UHFFFAOYSA-N Copy
• CAS Registry Number: 598-25-4
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
  The 3d structure may be viewed using Java or Javascript.
• Other names: 1,1-Dimethylallene; 1,1-Dimethylallylene; 2-Methyl-2,3-butadiene; 3-Methyl-1,2-butadiene; 3,3-Dimethylallene; CH2=C=C(CH3)2; 3-methylbuta-1,2-diene
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• Information on this page:
  • Condensed phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • IR Spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Gas Phase Kinetics Database
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Condensed 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of liquid

Phase change 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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of vaporization

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (bar)
    T = temperature (K)

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Enthalpy of fusion

Entropy of fusion

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 compiled by: Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi

View reactions leading to C₅H₈⁺ (ion structure unspecified)

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, Condensed phase thermochemistry data, Phase change 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.

Good, 1969
Good, W.D., 3-Methyl-1,2-butadiene: Enthalpies of combustion and formation, J. Chem. Eng. Data, 1969, 14, 480-481. [all data]

Messerly, Todd, et al., 1970
Messerly, J.F.; Todd, S.S.; Guthrie, G.B., Chemical thermodynamic properties of the pentadienes, J. Chem. Eng. Data, 1970, 15, 227-232. [all data]

Streiff, Schultz, et al., 1957
Streiff, A.J.; Schultz, L.H.; Hulme, A.R.; Tucker, J.A.; Krouskop, N.C.; Rossini, F.D., Purification, Purity, and Freezing Points of 20 API Standard API Research Hydrocarbons, Anal. Chem., 1957, 29, 361. [all data]

Messerly, Todd, et al., 1970, 2
Messerly, J.F.; Todd, S.S.; Guthrie, G.B., Chemical thermodynamic properties of the pentadienes. Third law studies., J. Chem. Eng. Data, 1970, 15, 227-32. [all data]

Steele, Chirico, et al., 1990
Steele, W.V.; Chirico, R.D.; Nguyen, A.; Hossenlopp, I.A.; Smith, N.K., Determination of ideal-gas enthalpies of formation for key compounds, Am. Inst. Chem. Eng. Symp. Ser. (AIChE Symp. Ser.), 1990, 138-154. [all data]

Reid, 1972
Reid, Robert C., Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00, AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637 . [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Osborn and Douslin, 1969
Osborn, Ann G.; Douslin, Donald R., Vapor pressure relations for the seven pentadienes, J. Chem. Eng. Data, 1969, 14, 2, 208-209, https://doi.org/10.1021/je60041a010 . [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [all data]

Harris, McKinnon, et al., 1979
Harris, D.; McKinnon, S.; Boyd, R.K., The origins of the base peak in the electron impact spectrum of limonene, Org. Mass Spectrom., 1979, 14, 265. [all data]

Bieri, Burger, et al., 1977
Bieri, G.; Burger, F.; Heilbronner, E.; Maier, J.P., Valence ionization enrgies of hydrocarbons, Helv. Chim. Acta, 1977, 60, 2213. [all data]

Brogli, Crandall, et al., 1973
Brogli, F.; Crandall, J.K.; Heilbronner, E.; Kloster-Jensen, E.; Sojka, S.A., The photoelectron spectra of methyl-substituted allenes and of tetramethyl-bisallenyl, J. Electron Spectrosc. Relat. Phenom., 1973, 2, 455. [all data]

Notes

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• Symbols used in this document:
  

  Cp,liquid	Constant pressure heat capacity of liquid
  S°liquid	Entropy of liquid at standard conditions
  Tboil	Boiling point
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions

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