1-Propene, 2-methyl-

• Formula: C₄H₈
• Molecular weight: 56.1063
• IUPAC Standard InChI: InChI=1S/C4H8/c1-4(2)3/h1H2,2-3H3 Copy

  
• IUPAC Standard InChIKey: VQTUBCCKSQIDNK-UHFFFAOYSA-N Copy
• CAS Registry Number: 115-11-7
• 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: Propene, 2-methyl-; γ-Butylene; Isobutene; Isobutylene; Isopropylidenemethylene; 1,1-Dimethylethylene; 2-Methyl-1-propene; 2-Methylpropene; iso-C4H8; Methylpropene; UN 1055; 1,1-Dimethylethene; 2-Methylpropylene
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• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Henry's Law data
  • Ion clustering data
  • IR Spectrum
  • UV/Visible spectrum
  • Vibrational and/or electronic energy levels
  • Gas Chromatography
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Electron-Impact Ionization Cross Sections (on physics web site)
  • Gas Phase Kinetics Database
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Gas phase thermochemistry data

Go To: Top, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes

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

Constant pressure heat capacity of gas

Phase change data

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

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:
DH - Eugene S. Domalski and Elizabeth D. Hearing
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Enthalpy of vaporization

Antoine Equation Parameters

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

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Enthalpy of fusion

Entropy of fusion

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), References, Notes

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:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to C₄H₈⁺ (ion structure unspecified)

Proton affinity at 298K

Gas basicity at 298K

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₄H₇^- +  =

By formula: C₄H₇^- + H⁺ = C₄H₈

Mass spectrum (electron ionization)

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, References, Notes

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, 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.

Prosen, Maron, et al., 1951
Prosen, E.J.; Maron, F.W.; Rossini, F.D., Heats of combustion, formation, and insomerization of ten C₄ hydrocarbons, J. Res. NBS, 1951, 46, 106-112. [all data]

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Guinchant, M.J., Etude sur la fonction acide dans les derives metheniques et methiniques, Ann. Chem., 1918, 10, 30-84. [all data]

Stull D.R., 1969
Stull D.R., Jr., The Chemical Thermodynamics of Organic Compounds. Wiley, New York, 1969. [all data]

Todd S.S., 1936
Todd S.S., Thermal data on organic compounds. XV. Some heat capacity, entropy and free energy data for the isomeric butenes, J. Am. Chem. Soc., 1936, 58, 134-137. [all data]

Thermodynamics Research Center, 1997
Thermodynamics Research Center, Selected Values of Properties of Chemical Compounds., Thermodynamics Research Center, Texas A&M University, College Station, Texas, 1997. [all data]

Kilpatrick J.E., 1946
Kilpatrick J.E., Heat content, free energy function, entropy, and heat capacity of ethylene, propylene, and the four butenes to 1500 K, J. Res. Nat. Bur. Stand, 1946, 37, 163-171. [all data]

East A.L.L., 1997
East A.L.L., Ab initio statistical thermodynamical models for the computation of third-law entropies, J. Chem. Phys., 1997, 106, 6655-6674. [all data]

Scott R.B., 1945
Scott R.B., Specific heats of gaseous 1,3-butadiene, isobutene, styrene, and ethylbenzene, J. Res. Nat. Bur. Stand., 1945, 34, 243-254. [all data]

Rabinovich and Lebedev, 1971
Rabinovich, I.B.; Lebedev, B.V., On the thermodynamic stability of polyisobutylene. Tr. Khim. Khim. Tekhnol., 1971, 194-196. [all data]

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Kistiakowsky, G.B.; Ruhoff, J.R.; Smith, H.A.; Vaughan, W.E., Heats of Organic Reactions II. Hydrogenation of Some Simpler Olefinic Hydrocarbons, J. Am. Chem. Soc., 1935, 57, 876-82. [all data]

Coffin and Maass, 1928
Coffin, C.C.; Maass, O., The Preparation and Physical Properties of α-,β- and γ-Butylene and Normal and Isobutane, J. Am. Chem. Soc., 1928, 50, 1427-37. [all data]

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Todd, S.S.; Parks, G.S., Thermal Data on Organic Compounds XV. Some Heat Capacity, Entropy and Free Energy Data for the Isomeric Butenes, J. Am. Chem. Soc., 1936, 58, 134. [all data]

Tsonopoulos and Ambrose, 1996
Tsonopoulos, C.; Ambrose, D., Vapor-Liquid Critical Properties of Elements and Compounds. 6. Unsaturated Aliphatic Hydrocarbons, J. Chem. Eng. Data, 1996, 41, 645-656. [all data]

Beattie, Ingersoll, et al., 1942
Beattie, J.A.; Ingersoll, H.G.; Stockmayer, W.H., Vapor Pressure and Critical Consants of Isobutene, J. Am. Chem. Soc., 1942, 64, 546. [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]

Beattie, Ingersoll, et al., 1942, 2
Beattie, James A.; Ingersoll, Henry G.; Stockmayer, Walter H., Vapor Pressures and Critical Constants of Isobutene, J. Am. Chem. Soc., 1942, 64, 3, 546-548, https://doi.org/10.1021/ja01255a021 . [all data]

Lamb and Roper, 1940
Lamb, Arthur B.; Roper, Edwin E., The Vapor Pressures of Certain Unsaturated Hydrocarbons, J. Am. Chem. Soc., 1940, 62, 4, 806-814, https://doi.org/10.1021/ja01861a032 . [all data]

Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E., The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [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]

Todd and Parks, 1936, 2
Todd, S.S.; Parks, G.S., Thermal data on organic compounds. XV. Some heat capacity, entropy and free energy data for the isomeric butenes, J. Am. Chem. Soc., 1936, 58, 134-137. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Bouchoux and Salpin, 1999
Bouchoux, J.; Salpin, J.Y., Re-evaluated gas-phase basicity and proton affinity data from the thermokinetic method, Rapid Com. Mass Spectrom., 1999, 13, 932. [all data]

Cleven, Hoke, et al., 1996
Cleven, C.D.; Hoke, S.H.; Cooks, R.G.; Hrovat, D.A.; Smith, J.M.; Lee, M.S.; Borden, W.T., Effect of Olefin Pyramidalization on the Proton Affinity of Tricyclo[3.3.3.03,7]undec-3(7)-ene as Determined by ab Initio Calculations and Kinetic Method Measurements, J. Am. Chem. Soc., 1996, 118, 10872. [all data]

Traeger, 1986
Traeger, J.C., Heat of formation for the 1-methylallyl cation by photoionization mass spectrometry, J. Phys. Chem., 1986, 90, 4114. [all data]

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Holmes, J.L.; Lossing, F.P., The need for adequate thermochemical data for the interpretation of fragmentation mechanisms and ion structure assignments, Int. J. Mass Spectrom. Ion Phys., 1983, 47, 133. [all data]

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Lossing, 1972
Lossing, F.P., Free radicals by mass spectrometry. XLV. Ionization potentials and heats of formation of C₃H₃, C₃H₅, and C₄H₇ radicals and ions, Can. J. Chem., 1972, 50, 3973. [all data]

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Frost, D.C.; Sandhu, J.S., Ionization potentials of ethylene and some methyl-substituted ethylenes as determined by photoelectron spectroscopy, Indian J. Chem., 1971, 9, 1105. [all data]

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Wiberg, K.B.; Ellison, G.B.; Wendoloski, J.J.; Brundle, C.R.; Kuebler, N.A., Electronic states of organic molecules. 3. Photoelectron spectra of cycloalkenes and methylenecycloalkanes, J. Am. Chem. Soc., 1976, 98, 7179. [all data]

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Kimura, K.; Katsumata, S.; Yamazaki, T.; Wakabayashi, H., UV photoelectron spectra and sum rule consideration; out-of-plane orbitals of unsaturated compounds with planar-skeleton structure, J. Electron Spectrosc. Relat. Phenom., 1975, 6, 41. [all data]

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Meisels, G.G.; Park, J.Y.; Giessner, B.G., Ionization and dissociation of C₄H₈ isomers, J. Am. Chem. Soc., 1970, 92, 254. [all data]

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Traeger, J.C., A study of the allyl cation thermochemistry by photoionization mass spectrometry, Int. J. Mass Spectrom. Ion Processes, 1984, 58, 259. [all data]

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Holmes, J.L.; Weese, G.M.; Blair, A.S.; Terlouw, J.K., Metastable ion studies IX-Thermochemistry and ion structures among fragmenting [C₄H₈]⁺ ions, an electron impact and field ionization investigation, Org. Mass Spectrom., 1977, 12, 424. [all data]

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Notes

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

• Symbols used in this document:
  

  AE	Appearance energy
  Cp,gas	Constant pressure heat capacity of gas
  IE (evaluated)	Recommended ionization energy
  Pc	Critical pressure
  S°gas	Entropy of gas at standard conditions
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Vc	Critical volume
  ΔcH°gas	Enthalpy of combustion of gas at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions
  ρc	Critical density

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