Acetaldehyde

• Formula: C₂H₄O
• Molecular weight: 44.0526
• IUPAC Standard InChI: InChI=1S/C2H4O/c1-2-3/h2H,1H3 Copy

  
• IUPAC Standard InChIKey: IKHGUXGNUITLKF-UHFFFAOYSA-N Copy
• CAS Registry Number: 75-07-0
• 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: Acetic aldehyde; Ethanal; Ethyl aldehyde; CH3CHO; Acetaldehyd; Aldehyde acetique; Aldeide acetica; NCI-C56326; Octowy aldehyd; Acetylaldehyde; Rcra waste number U001; UN 1089; NSC 7594
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• Information on this page:
  • Phase change data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • 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:
  • Gas Phase Kinetics Database
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Phase change data

Go To: Top, 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
DRB - Donald R. Burgess, Jr.
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
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis

Enthalpy of vaporization

Antoine Equation Parameters

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

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Enthalpy of fusion

Entropy of fusion

Entropy of fusion

Enthalpy of phase transition

Entropy of phase transition

Gas phase ion energetics data

Go To: Top, 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
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 C₂H₄O⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₂H₃O^- +  =

By formula: C₂H₃O^- + H⁺ = C₂H₄O

C₂H₃O^- +  =

By formula: C₂H₃O^- + H⁺ = C₂H₄O

Mass spectrum (electron ionization)

Go To: Top, 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, 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.

Teja and Anselme, 1990
Teja, A.S.; Anselme, M.J., The critical properties of thermally stable and unstable fluids. I. 1985 results, AIChE Symp. Ser., 1990, 86, 279, 115-21. [all data]

Hollmann, 1903
Hollmann, R., Physical and natural equilibria between the modifications of aldehyde, Z. Phys. Chem., Stoechiom. Verwandtschaftsl., 1903, 43, 129-59. [all data]

Van der Waals, 1881
Van der Waals, J.D., Continuity of Gas and Liquid Data, 1881,, 1881, Leipzig, p 168. [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]

Wiberg, Crocker, et al., 1991
Wiberg, K.B.; Crocker, L.S.; Morgan, K.M., Thermochemical studies of carbonyl compounds. 5. Enthalpies of reduction of carbonyl groups, J. Am. Chem. Soc., 1991, 113, 3447-3450. [all data]

Bull, Seregrennaja, et al., 1963
Bull, S.S.; Seregrennaja, I.I.; Tsherbakora, P.R., Khim. Prom. (Moscow), 1963, 7, 507. [all data]

Verevkin, Krasnykh, et al., 2003
Verevkin, Sergey P.; Krasnykh, Eugen L.; Vasiltsova, Tatiana V.; Koutek, Bohumir; Doubsky, Jan; Heintz, Andreas, Vapor pressures and enthalpies of vaporization of a series of the linear aliphatic aldehydes, Fluid Phase Equilibria, 2003, 206, 1-2, 331-339, https://doi.org/10.1016/S0378-3812(03)00035-9 . [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]

Dykyj, 1970
Dykyj, J., Petrochemica, 1970, 10, 2, 51. [all data]

Kim and Kim, 1977
Kim, B.C.; Kim, D.H., Hwahak Kwa Hwahak Kongop, 1977, 20, 232. [all data]

Coles and Popper, 1950
Coles, K.F.; Popper, Felix, Vapor-Liquid Equilibria. Ethylene Oxide - Acetaldehyde and Ethylene Oxide - Water Systems, Ind. Eng. Chem., 1950, 42, 7, 1434-1438, https://doi.org/10.1021/ie50487a046 . [all data]

Coleman and DeVries, 1949
Coleman, C.F.; DeVries, T., The heat capacity of organic vapors. V. Acetaldehyde, J. Am. Chem. Soc., 1949, 71, 2839-28. [all data]

Bull, Seregrennaja, et al., 1963, 2
Bull, S.Sh.; Seregrennaja, I.I.; Tsherbakora, P.R., Isothermic Equilibrium of Liquid-Steam in System Water-Acetoaldehyde, Khim. Prom. (Moscow), 1963, 7, 507-509. [all data]

Lebedev and Vasil'ev, 1988
Lebedev, B.V.; Vasil'ev, V.G., Thermodynamics of ethanal at 0-300 K, Zhur. Fiz. Khim., 1988, 62, 3099-3102. [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]

Desfrancois, Abdoul-Carime, et al., 1994
Desfrancois, C.; Abdoul-Carime, H.; Khelifa, N.; Schermann, J.P., Fork 1/r to 1/r2 Potentials: Electron Exchange between Rydberg Atoms and Polar Molecules, Phys. Rev. Lett., 1994, 73, 18, 2436, https://doi.org/10.1103/PhysRevLett.73.2436 . [all data]

Traeger, 1985
Traeger, J.C., Heat of formation for the formyl cation by photoionization mass spectrometry, Int. J. Mass Spectrom. Ion Processes, 1985, 66, 271. [all data]

Traeger, McLouglin, et al., 1982
Traeger, J.C.; McLouglin, R.G.; Nicholson, A.J.C., Heat of formation for acetyl cation in the gas phase, J. Am. Chem. Soc., 1982, 104, 5318. [all data]

El-Sherbini, Allam, et al., 1981
El-Sherbini, T.M.; Allam, S.H.; Migahed, M.D.; Dawoud, A.M., Mass spectrometric investigation of aliphatic aldehydes, Z. Naturforsch. A:, 1981, 36, 1334. [all data]

Jochims, Lohr, et al., 1978
Jochims, H.-W.; Lohr, W.; Baumgartel, H., Photoionization mass spectrometry studies of deuterated acetaldehydes CH₃CDO and CD₃CHO, Chem. Phys. Lett., 1978, 54, 594. [all data]

Staley, Wieting, et al., 1977
Staley, R.H.; Wieting, R.D.; Beauchamp, J.L., Carbenium ion stabilities in the gas phase and solution. An ion cyclotron resonance study of bromide transfer reactions involving alkali ions, alkyl carbenium ions, acyl cations and cyclic halonium ions, J. Am. Chem. Soc., 1977, 99, 5964. [all data]

Hernandez, Masclet, et al., 1977
Hernandez, R.; Masclet, P.; Mouvier, G., Spectroscopie de photoelectrons d'aldehydes et de cetones aliphatiques, J. Electron Spectrosc. Relat. Phenom., 1977, 10, 333. [all data]

Holmes, Terlouw, et al., 1976
Holmes, J.L.; Terlouw, J.K.; Lossing, F.P., The thermochemistry of C₂H₄O⁺ ions, J. Phys. Chem., 1976, 80, 2860. [all data]

Meeks, Arnett, et al., 1975
Meeks, J.L.; Arnett, J.F.; Larson, D.; McGlynn, S.P., Photoelectron spectroscopy of carbonyls. Ionization assignments, Chem. Phys. Lett., 1975, 30, 190. [all data]

McGlynn and Meeks, 1975
McGlynn, S.P.; Meeks, J.L., Photoelectron spectra of carbonyls: Acetaldehyde, acetamide, biacetyl, pyruvic acid, methyl pyruvate and vamide, J. Electron Spectrosc. Relat. Phenom., 1975, 6, 269. [all data]

Warneck, 1974
Warneck, P., Heat of formation of the HCO radical, Z. Naturforsch. A:, 1974, 29, 350. [all data]

Tam, Yee, et al., 1974
Tam, W.-C.; Yee, D.; Brion, C.E., Photoelectron spectra of some aldehydes and ketones, J. Electron Spectrosc. Relat. Phenom., 1974, 4, 77. [all data]

Ogata, Kitayama, et al., 1974
Ogata, H.; Kitayama, J.; Koto, M.; Kojima, S.; Nihei, Y.; Kamada, H., Vacuum ultraviolet absorption and photoelectron spectra of aliphatic ketones, Bull. Chem. Soc. Jpn., 1974, 47, 958. [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]

Knowles and Nicholson, 1974
Knowles, D.J.; Nicholson, A.J.C., Ionization energies of formic and acetic acid monomers, J. Chem. Phys., 1974, 60, 1180. [all data]

Chadwick and Katrib, 1974
Chadwick, D.; Katrib, A., Photoelectron spectra of acetaldehyde and acetyl halides, J. Electron Spectrosc. Relat. Phenom., 1974, 3, 39. [all data]

Potapov and Sorokin, 1972
Potapov, V.K.; Sorokin, V.V., Kinetic energies of products of dissociative photoionization of molecules. I. Aliphatic ketones and alcohols, Khim. Vys. Energ., 1972, 6, 387. [all data]

Cocksey, Eland, et al., 1971
Cocksey, B.J.; Eland, J.H.D.; Danby, C.J., The effect of alkyl substitution on ionisation potential, J. Chem. Soc., 1971, (B), 790. [all data]

Matthews and Warneck, 1969
Matthews, C.S.; Warneck, P., Heats of formation of CHO⁺ and C₃H₃⁺ by photoionization, J. Chem. Phys. 5, 1969, 1, 854. [all data]

Dewar and Worley, 1969
Dewar, M.J.S.; Worley, S.D., Photoelectron spectra of molecules. I. Ionization potentials of some organic molecules and their interpretation, J. Chem. Phys., 1969, 50, 654. [all data]

Potapov, Filyugina, et al., 1968
Potapov, V.K.; Filyugina, A.D.; Shigorin, D.N.; Ozerova, G.A., Photoionization of some compounds containing the carbonyl and amino groups, Dokl. Akad. Nauk SSSR, 1968, 180, 398, In original 352. [all data]

Vilesov, 1960
Vilesov, F.I., The photoionization of vapors of compounds whose molecules contain carbonyl groups, Dokl. Phys. Chem., 1960, 132, 521, In original 1332. [all data]

Hurzeler, Inghram, et al., 1958
Hurzeler, H.; Inghram, M.G.; Morrison, J.D., Photon impact studies of molecules using a mass spectrometer, J. Chem. Phys., 1958, 28, 76. [all data]

Watanabe, 1957
Watanabe, K., Ionization potentials of some molecules, J. Chem. Phys., 1957, 26, 542. [all data]

Vilesov and Terenin, 1957
Vilesov, F.I.; Terenin, A.N., The photoionization of the vapors of certain organic compounds, Dokl. Akad. Nauk SSSR, 1957, 115, 744, In original 539. [all data]

Walsh, 1946
Walsh, A.D., The absorption spectrum of acetaldehyde in the vacuum ultra-violet, Proc. Roy. Soc. (London), 1946, A185, 176. [all data]

Johnson, Powis, et al., 1982
Johnson, K.; Powis, I.; Danby, C.J., A photoelectron-photoion coincidence study of acetaldehyde and ethylene oxide molecular ions, Chem. Phys., 1982, 70, 329. [all data]

Bieri, Asbrink, et al., 1982
Bieri, G.; Asbrink, L.; Von Niessen, W., 30.4-nm He(II) photoelectron spectra of organic molecules, J. Electron Spectrosc. Relat. Phenom., 1982, 27, 129. [all data]

Benoit and Harrison, 1977
Benoit, F.M.; Harrison, A.G., Predictive value of proton affinity. Ionization energy correlations involving oxygenated molecules, J. Am. Chem. Soc., 1977, 99, 3980. [all data]

Rao, 1975
Rao, C.N.R., Lone-pair ionization bands of chromophores in the photoelectron spectra of organic molecules, Indian J. Chem., 1975, 13, 950. [all data]

Kimura, Katsumata, et al., 1975
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]

Bombach, Stadelmann, et al., 1981
Bombach, R.; Stadelmann, J.P.; Vogt, J., The fragmentation and isomerization of internal energy selected acetaldehyde molecular cations, Chem. Phys., 1981, 60, 293. [all data]

Haney and Franklin, 1969
Haney, M.A.; Franklin, J.L., Excess energies in mass spectra of some oxygen-containing organic compounds, J. Chem. Soc. Faraday Trans., 1969, 65, 1794. [all data]

Shigorin, Filyugina, et al., 1966
Shigorin, D.N.; Filyugina, A.D.; Potapov, V.K., Ionization and dissociation of molecules of acetaldehyde, acetone, and acetic acid on electron impact, Teor. i Eksperim. Khim., 1966, 2, 554, In original 417. [all data]

Dorman, 1965
Dorman, F.H., Fragment ions from CH₃CHO and (CH₃)₂CO by electron impact, J. Chem. Phys., 1965, 42, 65. [all data]

Burgers and Holmes, 1982
Burgers, P.C.; Holmes, J.L., Metastable ion studies. XIII. The measurement of appearance energies of metastable peaks, Org. Mass Spectrom., 1982, 17, 123. [all data]

Mead, Lykke, et al., 1984
Mead, R.D.; Lykke, K.R.; Lineberger, W.C.; Marks, J.; Brauman, J.I., Spectroscopy and Dynamics of the Dipole-Bound State of Acetaldehyde Enolate., J. Chem. Phys., 1984, 81, 11, 4883., https://doi.org/10.1063/1.447515 . [all data]

Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr., The gas phase acidity scale from methanol to phenol, J. Am. Chem. Soc., 1979, 101, 6047. [all data]

Holmes and Lossing, 1982
Holmes, J.L.; Lossing, F.P., Heats of formation of the ionic and neutral enols of acetaldehyde and acetone, J. Am. Chem. Soc., 1982, 104, 2648. [all data]

Cumming and Kebarle, 1978
Cumming, J.B.; Kebarle, P., Summary of gas phase measurements involving acids AH. Entropy changes in proton transfer reactions involving negative ions. Bond dissociation energies D(A-H) and electron affinities EA(A), Can. J. Chem., 1978, 56, 1. [all data]

Nimlos, Soderquist, et al., 1989
Nimlos, M.R.; Soderquist, J.A.; Ellison, G.B., Spectroscopy of CH3CO- and CH3CO, J. Am. Chem. Soc., 1989, 111, 20, 7675, https://doi.org/10.1021/ja00202a001 . [all data]

DePuy, Bierbaum, et al., 1985
DePuy, C.H.; Bierbaum, V.M.; Damrauer, R.; Soderquist, J.A., Gas-phase reactions of the acetyl anion, J. Am. Chem. Soc., 1985, 107, 3385. [all data]

Graul and Squires, 1990
Graul, S.T.; Squires, R.R., Gas-Phase Acidities Derived from Threshold Energies for Activated Reactions, J. Am. Chem. Soc., 1990, 112, 7, 2517, https://doi.org/10.1021/ja00163a007 . [all data]

Graul and Squires, 1988
Graul, S.T.; Squires, R.R., On the Existence of Alkyl Carbanions in the Gas Phase, J. Am. Chem. Soc., 1988, 110, 2, 607, https://doi.org/10.1021/ja00210a054 . [all data]

Notes

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

• Symbols used in this document:
  

  AE	Appearance energy
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy of phase transition
  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

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