Cyclopentane, methyl-

• Formula: C₆H₁₂
• Molecular weight: 84.1595
• IUPAC Standard InChI: InChI=1S/C6H12/c1-6-4-2-3-5-6/h6H,2-5H2,1H3 Copy

  
• IUPAC Standard InChIKey: GDOPTJXRTPNYNR-UHFFFAOYSA-N Copy
• CAS Registry Number: 96-37-7
• 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: Methylcyclopentane; UN 2298
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• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Henry's Law data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • IR Spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • 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:
DRB - Donald R. Burgess, Jr.
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

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
DRB - Donald R. Burgess, Jr.
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of vaporization

Enthalpy of vaporization

Δ_vapH = A exp(-βT_r) (1 − T_r)^β
    Δ_vapH = Enthalpy of vaporization (at saturation pressure) (kcal/mol)
    T_r = reduced temperature (T / T_c)

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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

Henry's Law 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: Rolf Sander

Henry's Law constant (water solution)

k_H(T) = k°_H exp(d(ln(k_H))/d(1/T) ((1/T) - 1/(298.15 K)))
k°_H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(k_H))/d(1/T) = Temperature dependence constant (K)

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:
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

View reactions leading to C₆H₁₂⁺ (ion structure unspecified)

Ionization energy determinations

Appearance 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, Condensed phase thermochemistry data, Phase change data, Henry's Law 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 and Smith, 1969
Good, W.D.; Smith, N.K., Enthalpies of combustion of toluene, benzene, cyclohexane, cyclohexene, methylcyclopentane, 1-methylcyclopentene, and n-hexane, J. Chem. Eng. Data, 1969, 14, 102-106. [all data]

Prosen, Johnson, et al., 1946
Prosen, E.J.; Johnson, W.H.; Rossini, F.D., Heats of formation and combustion of the normal alkylcyclopentanes and cyclohexanes and the increment per CH₂ group for several homologous series of hydrocarbons, J. Res. NBS, 1946, 37, 51-56. [all data]

Moore, Renquist, et al., 1940
Moore, G.E.; Renquist, M.L.; Parks, G.S., Thermal data on organic compounds. XX. Modern combustion data for two methylnonanes, methyl ethyl ketone, thiophene and six cycloparaffins, J. Am. Chem. Soc., 1940, 62, 1505-1507. [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]

Scott D.W., 1960
Scott D.W., Chemical thermodynamic properties of methylcyclopentane and 1-cis-3-dimethylcyclopentane, J. Phys. Chem., 1960, 64, 906-908. [all data]

McCullough J.P., 1959
McCullough J.P., Thermodynamics of cyclopentane, methylcyclopentane and 1,cis-3-dimethylcyclopentane: verification of the concept of pseudorotation, J. Am. Chem. Soc., 1959, 81, 5880-5883. [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]

Moore and Parks, 1939
Moore, G.E.; Parks, G.S., New thermodynamic data for the cyclohexane-methylcyclopentane isomerization, J. Am. Chem. Soc., 1939, 61, 2561-2562. [all data]

Zubova, 1901
Zubova, P., Data about heat of combustion of compound cycle structure, Zh. Fiz. Khim., 1901, 33, 708-722. [all data]

Douslin and Huffman, 1946
Douslin, D.R.; Huffman, H.M., The heat capacities, heats of transition, heats of fusion and entropies of cyclopentane, methylcyclopentane and methylcylohexane, J. Am. Chem. Soc., 1946, 68, 173-176. [all data]

Huffman, Parks, et al., 1931
Huffman, H.M.; Parks, G.S.; Barmore, M., Thermal data on organic compounds. X. Further studies on the heat capacities, entropies and free energies of hydrocarbons, J. Am. Chem. Soc., 1931, 53, 3876-3888. [all data]

Siddiqi, Svejda, et al., 1983
Siddiqi, M.A.; Svejda, P.; Kohler, F., A generalized van der Waals equation of state II. Excess heat capacities of mixtures containing cycloalkanes (C5,C6), methylcycloalkanes (C5,C6) and n-decane, Ber. Bunsenges. Phys. Chem., 1983, 87, 1176-1181. [all data]

Connolly, Sage, et al., 1951
Connolly, T.J.; Sage, B.H.; Lacey, W.N., Isobaric heat capacities at bubble point. n-Hexane, methylcyclopentane, and n-octane, Ind. Eng. Chem., 1951, 43, 946-950. [all data]

Daubert, 1996
Daubert, T.E., Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes, J. Chem. Eng. Data, 1996, 41, 365-372. [all data]

Majer and Svoboda, 1985
Majer, V.; Svoboda, V., Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]

Kudchadker, Alani, et al., 1968
Kudchadker, A.P.; Alani, G.H.; Zwolinski, B.J., The Critical Constants of Organic Substances, Chem. Rev., 1968, 68, 659. [all data]

Ambrose, Cox, et al., 1960
Ambrose, D.; Cox, J.D.; Townsend, R., The critical temperatures of forty organic compounds, Trans. Faraday Soc., 1960, 56, 1452. [all data]

Kay, 1947
Kay, W.B., Vapor Pressures and Saturated Liquid and Vapor DEensities of Cyclopentane, Methylcyclopentane, Ethylcyclopentane, and Methylcyclohexane, J. Am. Chem. Soc., 1947, 69, 1273-7. [all data]

Sapei, Uusi-Kyyny, et al., 2010
Sapei, Erlin; Uusi-Kyyny, Petri; Keskinen, Kari I.; Alopaeus, Ville, Phase equilibria of binary systems of 3-methylthiophene with four different hydrocarbons, Fluid Phase Equilibria, 2010, 288, 1-2, 155-160, https://doi.org/10.1016/j.fluid.2009.11.004 . [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]

Willingham, Taylor, et al., 1945
Willingham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D., Vapor pressures and boiling points of some paraffin, alkylcyclopentane, alkylcyclohexane, and alkylbenzene hydrocarbons, J. RES. NATL. BUR. STAN., 1945, 35, 3, 219-17, https://doi.org/10.6028/jres.035.009 . [all data]

McCullough, Pennington, et al., 1959
McCullough, J.P.; Pennington, R.E.; Smith, J.C.; Hossenlopp, I.A.; Waddington, G., Thermodynamics of cyclopentane, methylcyclopentane and 1,cis-3-dimethylcyclopentane: Verification of the concept of pseudorotation, J. Am. Chem. Soc., 1959, 81, 5880-5883. [all data]

Williamham, Taylor, et al., 1945
Williamham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D., Vapor Pressures and Boiling Points of Some Paraffin, Alkylcyclopentane, Alkylcyclohexane, and Alkylbenzene Hydrocarbons, J. Res. Natl. Bur. Stand. (U.S.), 1945, 35, 3, 219-244, https://doi.org/10.6028/jres.035.009 . [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]

Holmes and Lossing, 1991
Holmes, J.L.; Lossing, F.P., Ionization energies of homologous organic compounds and correlation with molecular size, Org. Mass Spectrom., 1991, 26, 537. [all data]

Lias, Ausloos, et al., 1976
Lias, S.G.; Ausloos, P.; Horvath, Z., Charge transfer reactions in alkane and cycloalkane systems. Estimated ionization potentials, Int. J. Chem. Kinet., 1976, 8, 725. [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]

Rang, Paldoia, et al., 1974
Rang, S.; Paldoia, P.; Talvari, A., Ionization potentials of unsaturated hydrocarbons. 2. Mono-substituted cyclopentenes and cyclohexenes, Eesti. NSV Tead. Akad. Toim., 1974, 354. [all data]

Pottie, Harrison, et al., 1961
Pottie, R.F.; Harrison, A.G.; Lossing, F.P., Free radicals by mass spectrometry. XXIV. Ionization potentials of cycloalkyl free radicals and cycloalkanes, J. Am. Chem. Soc., 1961, 83, 3204. [all data]

Lossing and Traeger, 1975, 2
Lossing, F.P.; Traeger, J.C., Free radicals by mass spectrometry XLVI. Heats of formation of C₅H₇ and C₅H₉ radicals and cations., J. Am. Chem. Soc., 1975, 19, 9. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Henry's Law 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
  Cp,liquid	Constant pressure heat capacity of liquid
  IE (evaluated)	Recommended ionization energy
  Pc	Critical pressure
  S°liquid	Entropy of liquid at standard conditions
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Vc	Critical volume
  d(ln(kH))/d(1/T)	Temperature dependence parameter for Henry's Law constant
  k°H	Henry's Law constant at 298.15K
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas 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
  ρc	Critical density

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