Isoprene

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Phase change data

Go To: Top, 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 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

Quantity Value Units Method Reference Comment
Tboil307. ± 2.KAVGN/AAverage of 17 values; Individual data points
Quantity Value Units Method Reference Comment
Tfus131. ± 20.KAVGN/AAverage of 7 values; Individual data points
Quantity Value Units Method Reference Comment
Ttriple127.27KN/AMesserly, Todd, et al., 1970Uncertainty assigned by TRC = 0.05 K; TRC
Ttriple126.4KN/ABekkedahl and Wood, 1937Uncertainty assigned by TRC = 0.2 K; TRC
Quantity Value Units Method Reference Comment
Δvap6.31kcal/molN/AReid, 1972AC
Δvap6.40 ± 0.06kcal/molVRogers, 1971ALS

Enthalpy of vaporization

ΔvapH (kcal/mol) Temperature (K) Method Reference Comment
7.03239.AStephenson and Malanowski, 1987Based on data from 221. to 254. K.; AC
6.76269.AStephenson and Malanowski, 1987Based on data from 254. to 316. K.; AC
7.53225.IPOsborn and Douslin, 1969Based on data from 216. to 235. K.; AC
6.52299.MMForziati, Camin, et al., 1950Based on data from 290. to 308. K.; AC
6.55288.N/AKuchinskaya, 1938Based on data from 258. to 318. K.; AC
6.17307.2VBekkedahl, Wood, et al., 1936ALS

Antoine Equation Parameters

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

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Temperature (K) A B C Reference Comment
215.6 to 234.924.082511108.151-35.731Osborn and Douslin, 1969Coefficents calculated by NIST from author's data.
289.9 to 307.3.21015706.92-87.046Gubkov, Fermor, et al., 1964Coefficents calculated by NIST from author's data.

Enthalpy of fusion

ΔfusH (kcal/mol) Temperature (K) Reference Comment
1.1770127.27Messerly, Todd, et al., 1970, 2DH
1.154126.4Warfield and Petree, 1965DH
1.154126.4Bekkedahl and Wood, 1937, 2DH
1.18127.3Domalski and Hearing, 1996AC

Entropy of fusion

ΔfusS (cal/mol*K) Temperature (K) Reference Comment
9.2481127.27Messerly, Todd, et al., 1970, 2DH
9.132126.4Warfield and Petree, 1965DH
9.132126.4Bekkedahl and Wood, 1937, 2DH

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:


Gas phase ion energetics data

Go To: Top, Phase change data, 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
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard

View reactions leading to C5H8+ (ion structure unspecified)

Quantity Value Units Method Reference Comment
IE (evaluated)8.86 ± 0.02eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)197.5kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity190.6kcal/molN/AHunter and Lias, 1998HL

Ionization energy determinations

IE (eV) Method Reference Comment
8.85 ± 0.02PEBieri, Burger, et al., 1977LLK
8.85EILossing and Traeger, 1975LLK
8.90 ± 0.10EIPuttemans and Delvaux, 1973LLK
8.89PEBeez, Bieri, et al., 1973LLK
8.845 ± 0.005PIWatanabe, Nakayama, et al., 1962RDSH
8.84 ± 0.01SPrice and Walsh, 1940RDSH
8.85PEWerstiuk, Clark, et al., 1990Vertical value; LL
8.85PEMasclet, Mouvier, et al., 1981Vertical value; LLK
8.87PEWorley, Webb, et al., 1979Vertical value; LLK
9.04PESustmann and Schubert, 1972Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C3H3+14.55 ± 0.15C2H4+HEIPuttemans and Delvaux, 1973LLK
C3H4+12.39 ± 0.12C2H4EIPuttemans and Delvaux, 1973LLK
C3H5+14.04 ± 0.10C2H2+HEIPuttemans and Delvaux, 1973LLK
C3H6+12.76 ± 0.10C2H2EIPuttemans and Delvaux, 1973LLK
C4H5+11.44CH3EILossing and Holmes, 1984LBLHLM
C4H5+11.93 ± 0.10CH3EIPuttemans and Delvaux, 1973LLK
C5H5+13.9H2+HEIHarrison, Haynes, et al., 1965RDSH
C5H7+10.54HEILossing and Traeger, 1975LLK
C5H7+10.54HEIHolmes, 1974LLK
C5H7+10.93 ± 0.10HEIPuttemans and Delvaux, 1973LLK

De-protonation reactions

C5H7- + Hydrogen cation = Isoprene

By formula: C5H7- + H+ = C5H8

Quantity Value Units Method Reference Comment
Δr385.6 ± 5.1kcal/molG+TSBartmess and McIver Jr., 1979gas phase; Between H2O, MeOH. Acid: isoprene; B
Quantity Value Units Method Reference Comment
Δr379.0 ± 5.0kcal/molIMRBBartmess and McIver Jr., 1979gas phase; Between H2O, MeOH. Acid: isoprene; B

References

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

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

Messerly, Todd, et al., 1970
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
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]

Messerly, Todd, et al., 1970, 2
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, 2
Bekkedahl, N.; Wood, L.A., Entropy of isoprene from heat-capacity measurements, J. Res. NBS, 1937, 19, 551-558. [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]

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]

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]

Lossing and Traeger, 1975
Lossing, F.P.; Traeger, J.C., Stabilization in cyclopentadienyl, cyclopentenyl, and cyclopentyl cations, J. Am. Chem. Soc., 1975, 97, 1579. [all data]

Puttemans and Delvaux, 1973
Puttemans, J.-P.; Delvaux, J.C., Ionisation et fragmentation d'isomeres C5H8 sous impact electronique. Spiropentane - methylenecyclobutane - isoprene, Ing. Chim. Brussell, 1973, 55(267-8), 7. [all data]

Beez, Bieri, et al., 1973
Beez, M.; Bieri, G.; Bock, H.; Heilbronner, E., The ionization potentials of butadiene, hexatriene, andtheir methyl derivatives: evidence for through space interaction between double bond π-orbitals and non-bonded pseudo-π orbitals of methyl groups?, Helv. Chim. Acta, 1973, 56, 1028. [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]

Price and Walsh, 1940
Price, W.C.; Walsh, A.D., The absorption spectra of conjugated dienes in the vacuum ultra-violet (1), Proc. Roy. Soc. (London), 1940, A174, 220. [all data]

Werstiuk, Clark, et al., 1990
Werstiuk, N.H.; Clark, K.B.; Leigh, W.J., Conformational analysis and structure elucidation of 2,3-dimethyl and 2,4-dimethyl-2,4-hexadienes by AM1 and He(I) ultraviolet photoelectron spectroscopy, Can. J. Chem., 1990, 68, 2078. [all data]

Masclet, Mouvier, et al., 1981
Masclet, P.; Mouvier, G.; Bocquet, J.F., Effets electroniques et effets steriques dus a la substitution alcoyle dans les dienes conjugues, J. Chim. Phys., 1981, 78, 99. [all data]

Worley, Webb, et al., 1979
Worley, S.D.; Webb, T.R.; Gibson, D.H.; Ong, T.-S., On the electronic structures of cyclobutadiene trimethylenemethane, J. Organomet. Chem., 1979, 168, 16. [all data]

Sustmann and Schubert, 1972
Sustmann, R.; Schubert, R., Photoelektronenspektroskopische bestimmung von substituenten-effekten. I. Subtituierte butadiene, Tetrahedron Lett., 1972, 27, 2739. [all data]

Lossing and Holmes, 1984
Lossing, F.P.; Holmes, J.L., Stabilization energy and ion size in carbocations in the gas phase, J. Am. Chem. Soc., 1984, 106, 6917. [all data]

Harrison, Haynes, et al., 1965
Harrison, A.G.; Haynes, P.; McLean, S.; Meyer, F., The mass spectra of methyl-substituted cyclopentadienes, J. Am. Chem. Soc., 1965, 87, 5099. [all data]

Holmes, 1974
Holmes, J.L., The mass spectra of isomeric hydrocarbons - II: The C5H8 isomers, spiropentane, cyclopentene, 1,3-pentadiene and isoprene; the mechanisms and energetics of their fragmentations, Org. Mass Spectrom., 1974, 8, 247. [all data]

Bartmess and McIver Jr., 1979
Bartmess, J.E.; McIver Jr., The Gas Phase Acidity Scale in Gas Phase Ion Chemistry, Gas Phase Ion Chemistry, V. 2, M.T. Bowers, Ed., Academic Press, NY, 1979, Ch. 11, Elsevier, 1979. [all data]


Notes

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