Cyclopropane

• Formula: C₃H₆
• Molecular weight: 42.0797
• IUPAC Standard InChI: InChI=1S/C3H6/c1-2-3-1/h1-3H2 Copy

  
• IUPAC Standard InChIKey: LVZWSLJZHVFIQJ-UHFFFAOYSA-N Copy
• CAS Registry Number: 75-19-4
• 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: Trimethylene; Trimethylene (cyclic); UN 1027; Cyclopropnane
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Henry's Law data
  • Gas phase ion energetics data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • Vibrational and/or electronic energy levels
  • Gas Chromatography
  • References
  • Notes
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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

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 by: 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of vaporization

Entropy of vaporization

Antoine Equation Parameters

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

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Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Reaction 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:
B - John E. Bartmess
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

C₃H₅^- +  =

By formula: C₃H₅^- + H⁺ = C₃H₆

 +  =

By formula: HBr + C₃H₆ = C₃H₇Br

=  + 

By formula: C₃H₆I₂ = C₃H₆ + I₂

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

Data compiled as indicated in comments:
B - John E. Bartmess
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 C₃H₆⁺ (ion structure unspecified)

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₃H₅^- +  =

By formula: C₃H₅^- + H⁺ = C₃H₆

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

• GAS; Not specified, most likely a prism, grating, or hybrid spectrometer.; DIGITIZED BY NIST FROM HARD COPY; 4 cm^-1 resolution
• GAS (100 mmHg DILUTED TO A TOTAL PRESSURE OF 400 mmHg WITH N2); DOW KBr FOREPRISM-GRATING; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution
• GAS (100 mmHg, N2 ADDED, TOTAL PRESSURE 600 mmHg); DOW KBr FOREPRISM-GRATING; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 2 cm^-1 resolution

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

Vibrational and/or electronic energy levels

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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: Takehiko Shimanouchi

Symmetry:   D_3h     Symmetry Number σ = 6

Source: Shimanouchi, 1972

Notes

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

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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, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), Vibrational and/or electronic energy levels, Gas Chromatography, Site Links, NIST Free Links, Notes

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

Lacher, Walden, et al., 1950
Lacher, J.R.; Walden, C.H.; Lea, K.R.; Park, J.D., Vapor phase heats of hydrobromination of cyclopropane and propylene, J. Am. Chem. Soc., 1950, 72, 331-333. [all data]

Knowlton and Rossini, 1949
Knowlton, J.W.; Rossini, F.D., Heats of combustion and formation of cyclopropane, J. Res. NBS, 1949, 43, 113-115. [all data]

Dorofeeva O.V., 1986
Dorofeeva O.V., Thermodynamic properties of twenty-one monocyclic hydrocarbons, J. Phys. Chem. Ref. Data, 1986, 15, 437-464. [all data]

Kobe K.A., 1950
Kobe K.A., Thermochemistry for the petrochemical industry. XIV. Some miscellaneous hydrocarbons, Petrol. Refiner, 1950, 29 (12), 93-96. [all data]

Kistiakowsky G.B., 1940
Kistiakowsky G.B., Gaseous heat capacities. II, J. Chem. Phys., 1940, 8, 610-618. [all data]

Kistiakowsky G.B., 1940, 2
Kistiakowsky G.B., The low temperature gaseous heat capacities of certain C3 hydrocarbons, J. Chem. Phys., 1940, 8, 970-977. [all data]

Ruehrwein and Powell, 1946
Ruehrwein, R.A.; Powell, T.M., The heat capacity, vapor pressure, heats of fusion and vaporization of cyclopropane. Entropy and density of the gas, J. Am. Chem. Soc., 1946, 68, 1063-1068. [all data]

Tickner and Lossing, 1951
Tickner, A.W.; Lossing, F.P., The Measurement of Low Vapor Pressures by Means of A Mass Spectrometer, J. Phys. Colloid Chem., 1951, 55, 733-40. [all data]

Ruehrwein and Powell, 1946, 2
Ruehrwein, R.A.; Powell, T.M., The heat capacity, vapor pressure, heats of fusion and vaporization of cyclopropane. Entropy and density of the gas, J. Am. Chem. Soc., 1946, 68, 1063-6. [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]

Lin, Silberberg, et al., 1970
Lin, D.C.K.; Silberberg, I.H.; McKetta, J.J., Volumetric Behavior, Vapor Pressure and Critical Properties of Cyclopropane, J. Chem. Eng. Data, 1970, 15, 483. [all data]

Booth and Morris, 1958
Booth, H.S.; Morris, W.C., The Critical Constants and Vapor Pressure of Cyclopropane, J. Phys. Chem., 1958, 62, 875. [all data]

Horneg, 1941
Horneg, A.G., Personal Communication, A. G. Horneg, Ohio Chem. & Mfg. Co., Phys. Constants of the Principal Hydrocarbons, 1941. [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]

Lin, Silberberg, et al., 1970, 2
Lin, David C.K.; Silberberg, I. Harold; McKetta, John J., Volumetric behavior, vapor pressures, and critical properties of cyclopropane, J. Chem. Eng. Data, 1970, 15, 4, 483-492, https://doi.org/10.1021/je60047a016 . [all data]

Calado, Filipe, et al., 1997
Calado, Jorge C.G.; Filipe, Eduardo J.M.; Lopes, José N.C., The vapour pressure of liquid cyclopropane, The Journal of Chemical Thermodynamics, 1997, 29, 12, 1435-1438, https://doi.org/10.1006/jcht.1997.0256 . [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]

Ruehrwein and Powell, 1946, 3
Ruehrwein, R.A.; Powell, T.M., The Heat Capacity, Vapor Pressure, Heats of Fusion and Vaporization of Cyclopropane. Entropy and Density of the Gas ¹, J. Am. Chem. Soc., 1946, 68, 6, 1063-1066, https://doi.org/10.1021/ja01210a044 . [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]

Bondi, 1963
Bondi, A., Heat of Siblimation of Molecular Crystals: A Catalog of Molecular Structure Increments., J. Chem. Eng. Data, 1963, 8, 3, 371-381, https://doi.org/10.1021/je60018a027 . [all data]

Tickner and Lossing, 1951, 2
Tickner, A.W.; Lossing, F.P., The Measurement of Low Vapor Pressures by Means of a Mass Spectrometer., J. Phys. Chem., 1951, 55, 5, 733-740, https://doi.org/10.1021/j150488a013 . [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]

Lacher, Kianpour, et al., 1957
Lacher, J.R.; Kianpour, A.; Park, J.D., Reaction heats of organic halogen compounds. X. Vapor phase heats of hydrobromination of cyclopropane and propylene, J. Phys. Chem., 1957, 61, 1124-1125. [all data]

Benson and Amano, 1962
Benson, S.W.; Amano, A., Thermodynamics of iodine addition to ethylene, propylene, and cyclopropane, J. Chem. Phys., 1962, 36, 3464-3471. [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]

Traeger, 1984
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]

Lias and Buckley, 1984
Lias, S.G.; Buckley, T.J., Structures and reactions of C₃H₆⁺ ions generated in cyclopropane, Int. J. Mass Spectrom. Ion Processes, 1984, 56, 123. [all data]

Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S., Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [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]

Rothgery, Holt, et al., 1975
Rothgery, E.F.; Holt, J.; McGee, H.A., Jr., Cryochemical synthesis and molecular energetics of cyclopropanone and some related compounds, J. Am. Chem. Soc., 1975, 97, 4971. [all data]

Krassig, Reinke, et al., 1974
Krassig, R.; Reinke, D.; Baumgartel, H., Photo-reaktionen kleiner organischer molekule II. Die photoionenspektren der Isomeren propylen-cyclopropan und acetaldehyd-athylenoxyd, Ber. Bunsen-Ges. Phys. Chem., 1974, 78, 425. [all data]

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]

Basch, Robin, et al., 1969
Basch, H.; Robin, M.B.; Kuebler, N.A.; Baker, C.; Turner, D.W., Optical and photoelectron spectra of small rings. III. The saturated three-membered rings, J. Chem. Phys., 1969, 51, 52. [all data]

Cermak, 1968
Cermak, V., Penning ionization electron spectroscopy. I. Determination of ionization potentials of polyatomic molecules, Collection Czech. Chem. Commun., 1968, 33, 2739. [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]

Plemenkov, Villem, et al., 1981
Plemenkov, V.V.; Villem, Y.Y.; Villem, N.V.; Bolesov, I.G.; Surmina, L.S.; Yakushkina, N.I.; Formanovskii, A.A., Photoelectron spectra of polyalkylcyclopropenes and polyalkylcyclopropanes, Zh. Obshch. Khim., 1981, 51, 2076. [all data]

Haney and Franklin, 1968
Haney, M.A.; Franklin, J.L., Correlation of excess energies of electron-impact dissociations with the translational energies of the products, J.Chem. Phys., 1968, 48, 4093. [all data]

Harrison and Tait, 1962
Harrison, A.G.; Tait, J.M.S., Concurrent ion-molecule reactions leading to the same product ion, Can. J. Chem., 1962, 40, 1986. [all data]

Buttrill, Williamson, et al., 1975
Buttrill, S.E., Jr.; Williamson, A.D.; LeBreton, P., Photoionization measurement of the heat of formation of allyl cations, J. Chem. Phys., 1975, 62, 1586. [all data]

Shimanouchi, 1972
Shimanouchi, T., Tables of Molecular Vibrational Frequencies Consolidated Volume I, National Bureau of Standards, 1972, 1-160. [all data]

Aflalaye, Sternberg, et al., 1995
Aflalaye, A.; Sternberg, R.; Raulin, F.; Vidal-Madjar, C., Gas chromatography of Titan's atmosphere. VI. Analysis of low-molecular-mass hydrocarbons and nitriles with BPX5 capillary columns, J. Chromatogr. A, 1995, 708, 2, 283-291, https://doi.org/10.1016/0021-9673(95)00410-O . [all data]

Do and Raulin, 1992
Do, L.; Raulin, F., Gas chromatography of Titan's atmosphere. III. Analysis of low-molecular-weight hydrocarbons and nitriles with a CP-Sil-5 CB WCOT capillary column, J. Chromatogr., 1992, 591, 1-2, 297-301, https://doi.org/10.1016/0021-9673(92)80247-R . [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]

Peng, Ding, et al., 1988
Peng, C.T.; Ding, S.F.; Hua, R.L.; Yang, Z.C., Prediction of Retention Indexes I. Structure-Retention Index Relationship on Apolar Columns, J. Chromatogr., 1988, 436, 137-172, https://doi.org/10.1016/S0021-9673(00)94575-8 . [all data]

Zenkevich, 2005
Zenkevich, I.G., Experimentally measured retention indices., 2005. [all data]

Zenkevich, Chupalov, et al., 1996
Zenkevich, I.G.; Chupalov, A.A.; Herzschuh, R., Correlation of the Increments of Gas Chromatographic Retention Indices with the Differences of Innermolecular Energies of Reagents and Products of Chemical Reactions, Zh. Org. Khim. (Rus.), 1996, 32, 11, 1685-1691. [all data]

Robinson and Odell, 1971
Robinson, P.G.; Odell, A.L., A system of standard retention indices and its uses. The characterisation of stationary phases and the prediction of retention indices, J. Chromatogr., 1971, 57, 1-10, https://doi.org/10.1016/0021-9673(71)80001-8 . [all data]

Peng, Yang, et al., 1991
Peng, C.T.; Yang, Z.C.; Ding, S.F., Prediction of rentention idexes. II. Structure-retention index relationship on polar columns, J. Chromatogr., 1991, 586, 1, 85-112, https://doi.org/10.1016/0021-9673(91)80028-F . [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), Vibrational and/or electronic energy levels, Gas Chromatography, Site Links, NIST Free Links, 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°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
  ΔsubH	Enthalpy of sublimation
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions
  ΔvapS	Entropy of vaporization
  ρc	Critical density

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