Isoprene

• Formula: C₅H₈
• Molecular weight: 68.1170
• IUPAC Standard InChI: InChI=1S/C5H8/c1-4-5(2)3/h4H,1-2H2,3H3 Copy

  
• IUPAC Standard InChIKey: RRHGJUQNOFWUDK-UHFFFAOYSA-N Copy
• CAS Registry Number: 78-79-5
• 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: 1,3-Butadiene, 2-methyl-; β-Methylbivinyl; Isopentadiene; 2-Methyl-1,3-butadiene; 2-Methylbutadiene; CH2=C(CH3)CH=CH2; 2-Methylbuta-1,3-diene; 3-Methyl-1,3-butadiene; NSC 9237
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• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering data
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Gas Phase Kinetics Database
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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

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:
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
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

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

IR Spectrum

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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

Gas Phase Spectrum

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Additional Data

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

UV/Visible spectrum

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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: Victor Talrose, Alexander N. Yermakov, Alexy A. Usov, Antonina A. Goncharova, Axlexander N. Leskin, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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Additional Data

Gas Chromatography

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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

Kovats' RI, non-polar column, isothermal

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Kovats' RI, non-polar column, custom temperature program

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Kovats' RI, polar column, isothermal

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Van Den Dool and Kratz RI, non-polar column, temperature ramp

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Normal alkane RI, non-polar column, isothermal

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Normal alkane RI, non-polar column, temperature ramp

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Normal alkane RI, non-polar column, custom temperature program

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Normal alkane RI, polar column, custom temperature program

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References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, Notes

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

Fraser and Prosen, 1955
Fraser, F.M.; Prosen, E.J., Heats of combustion and isomerization of six pentadienes and spiropentane, J. Res. NBS, 1955, 54, 143-148. [all data]

Messerly J.F., 1970
Messerly J.F., Chemical thermodynamic properties of the pentadienes. Third law studies, J. Chem. Eng. Data, 1970, 15, 227-232. [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]

Compton D.A.C., 1977
Compton D.A.C., Conformations of conjugated hydrocarbons. Part 2. A spectroscopic and thermodynamic study of cis- and trans-penta-1,3-diene, J. Chem. Soc. Perkin Trans. 2, 1977, 1311-1315. [all data]

Jessup, 1938
Jessup, R.S., Heat of combustion of isoprene, J. Res. NBS, 1938, 20, 589-597. [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]

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]

Warfield and Petree, 1965
Warfield, R.W.; Petree, M.C., Thermodynamic properties of natural rubber and isoprene, Die Makromol. Chemie, 1965, 84, 1-8. [all data]

Bekkedahl and Wood, 1937
Bekkedahl, N.; Wood, L.A., Entropy of isoprene from heat-capacity measurements, J. Res. NBS, 1937, 19, 551-558. [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]

Bekkedahl and Wood, 1937, 2
Bekkedahl, N.; Wood, L.A., Entropy of isoprene from heat-capacity measurements., J. Res. Natl. Bur. Stand. (U. S.), 1937, 19, 551. [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]

Rogers, 1971
Rogers, F.E., Thermochemistry of the Diels-Alder reaction. I. Enthalpy of addition of isoprene to tetracyanoethylene, J. Phys. Chem., 1971, 75, 1734-1737. [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]

Forziati, Camin, et al., 1950
Forziati, A.F.; Camin, D.L.; Rossini, F.D., Density, refractive index, boiling point, and vapor pressure of eight monoolefin (1-alkene), six pentadiene, and two cyclomonoolefin hydrocarbons, J. RES. NATL. BUR. STAN., 1950, 45, 5, 406, https://doi.org/10.6028/jres.045.044 . [all data]

Kuchinskaya, 1938
Kuchinskaya, K., Vapor pressures of pure substances, Sbornik Trudov Opytnogo Zavoda im. Akad. S. V. Lebedeva, 1938, 27-30. [all data]

Bekkedahl, Wood, et al., 1936
Bekkedahl, N.; Wood, L.A.; Wojciechowski, M., Some physical properties of isoprene, J. Res. NBS, 1936, 17, 883-894. [all data]

Gubkov, Fermor, et al., 1964
Gubkov, A.N.; Fermor, N.A.; Smirnov, N.I., Vapor Pressure of Mono-Poly Systems, Zh. Prikl. Khim. (Leningrad), 1964, 37, 2204-2210. [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]

Fihtengolts, et al., 1969
Fihtengolts, V.S., et al., Atlas of UV Absorption Spectra of Substances Used in Synthetic Rubber Manufacture, 1969, 9. [all data]

Heberger, 1990
Heberger, K., Identification of C₅H₈ Isomers Through Reactions of Singlet Methylene, CH₂(ã¹A₁), with Unsaturated Hydrocarbons Using Capillary Gas Chromatography - Mass Spectrometry, Analyst, 1990, 115, 6, 725-729, https://doi.org/10.1039/an9901500725 . [all data]

Safina, Poznyak, et al., 1989
Safina, L.R.; Poznyak, T.I.; Lisitsyn, D.M.; Kiseleva, E.V.; Kovalev, G.I., Selective gas-chromatographic determination of trace unsaturated and aromatic-hydrocarbons in complex-mixtures, J. Appl. Chem. USSR (Engl. Transl.), 1989, 44, 5, 749-754. [all data]

Papazova, Milina, et al., 1988
Papazova, D.; Milina, R.; Dimov, N., Comparative evaluation of retention of hydrocarbons present in the C₅-petroleum fraction of methylsilicone and squalane phases, Chromatographia, 1988, 25, 3, 177-180, https://doi.org/10.1007/BF02316441 . [all data]

Bredael, 1982
Bredael, P., Retention indices of hydrocarbons on SE-30, J. Hi. Res. Chromatogr. Chromatogr. Comm., 1982, 5, 6, 325-328, https://doi.org/10.1002/jhrc.1240050610 . [all data]

Bajus, Veselý, et al., 1979
Bajus, M.; Veselý, V.; Leclercq, P.A.; Rijks, J.A., Steam cracking of hydrocarbons. 2. Pyrolysis of methylcyclohexane, Ind. Eng. Chem. Prod. Res. Dev., 1979, 18, 2, 135-142, https://doi.org/10.1021/i360070a012 . [all data]

Schomburg and Dielmann, 1973
Schomburg, G.; Dielmann, G., Identification by means of retention parameters, J. Chromatogr. Sci., 1973, 11, 3, 151-159, https://doi.org/10.1093/chromsci/11.3.151 . [all data]

Hively and Hinton, 1968
Hively, R.A.; Hinton, R.E., Variation of the retention index with temperature on squalane substrates, J. Gas Chromatogr., 1968, 6, 4, 203-217, https://doi.org/10.1093/chromsci/6.4.203 . [all data]

Widmer, 1967
Widmer, H., Gas chromatographic identification of hydrocarbons using retention indices, J. Gas Chromatogr., 1967, 5, 10, 506-510, https://doi.org/10.1093/chromsci/5.10.506 . [all data]

Zulaïca and Guiochon, 1966
Zulaïca, J.; Guiochon, G., Analyse des hauts polymères par chromatographie en phase gazeuse de leurs produits de pyrolyse. II. Application à quelques hydrocarbures macromoléculaires purs, Bull. Soc. Chim. Fr., 1966, 4, 1351-1363. [all data]

Wehrli and Kováts, 1959
Wehrli, A.; Kováts, E., Gas-chromatographische Charakterisierung ogranischer Verbindungen. Teil 3: Berechnung der Retentionsindices aliphatischer, alicyclischer und aromatischer Verbindungen, Helv. Chim. Acta, 1959, 7, 7, 2709-2736, https://doi.org/10.1002/hlca.19590420745 . [all data]

Haagen-Smit Laboratory, 1997
Haagen-Smit Laboratory, Procedure for the detailed hydrocarbon analysis of gasolines by single column high efficiency (capillary) column gas chromatography, SOP NO. MLD 118, Revision No. 1.1, California Environmental Protection Agency, Air Resources Board, El Monte, California, 1997, 22. [all data]

Hoekman, 1993
Hoekman, S.K., Improved gas chromatography procedure for speciated hydrocarbon measurements of vehicle emissions, J. Chromatogr., 1993, 639, 2, 239-253, https://doi.org/10.1016/0021-9673(93)80260-F . [all data]

Helmig, Klinger, et al., 1999
Helmig, D.; Klinger, L.F.; Guenther, A.; Vierling, L.; Geron, C.; Zimmerman, P., Biogenic volatile organic compound emissions (BVOCs). I. Identifications from three continental sites in the U.S., Chemosphere, 1999, 38, 9, 2163-2187, https://doi.org/10.1016/S0045-6535(98)00425-1 . [all data]

Helmig, Pollock, et al., 1996
Helmig, D.; Pollock, W.; Greenberg, J.; Zimmerman, P., Gas chromatography mass spectrometry analysis of volatile organic trace gases at Mauna Loa Observatory, Hawaii, J. Geophys. Res., 1996, 101, D9, 14697-14710, https://doi.org/10.1029/96JD00212 . [all data]

Schomburg, 1966
Schomburg, G., Gaschromatographische Retentionsdaten und Struktur Chemischer Verbindungen. II. Methylverzweigungen und Doppelbindungen in Offenkettigen Kohlenwasserstoffen, J. Chromatogr., 1966, 23, 1-17, https://doi.org/10.1016/S0021-9673(01)98652-2 . [all data]

Bramston-Cook, 2013
Bramston-Cook, R., Kovats indices for C2-C13 hydrocarbons and selected oxygenated/halocarbons with 100 % dimethylpolysiloxane columns, 2013, retrieved from http://lotusinstruments.com/monographs/List .... [all data]

Supelco, 2012
Supelco, CatalogNo. 24160-U, Petrocol DH Columns. Catalog No. 24160-U, 2012, retrieved from http://www.sigmaaldrich.com/etc/medialib/docs/Supelco/Datasheet/1/w97949.Par.0001.File.tmp/w97949.pdf. [all data]

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Baraldi, R.; Rapparini, F.; Rossi, F.; Latella, A.; Ciccioli, P., Volatile organic compound emissions from flowers of the most occurring and economically important species of fruit trees, Phys. Chem. Earth, 1999, 24, 6, 729-732, https://doi.org/10.1016/S1464-1909(99)00073-8 . [all data]

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Orav, A.; Kailas, T.; Muurisepp, M.; Kann, J., Composition of the oil from waste tires. 1. Fraction boiling at yp to 160 0C, Proc. Estonian Acad. Sci. Chem., 1999, 48, 1, 30-39. [all data]

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Flanagan, R.J.; Streete, P.J.; Ramsey, J.D., Volatile Substance Abuse, UNODC Technical Series, No 5, United Nations, Office on Drugs and Crime, Vienna International Centre, PO Box 500, A-1400 Vienna, Austria, 1997, 56, retrieved from http://www.odccp.org/pdf/technical_series₁997-01-01₁.pdf. [all data]

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Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, References

• Symbols used in this document:
  

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