2-Butenal

• Formula: C₄H₆O
• Molecular weight: 70.0898
• IUPAC Standard InChI: InChI=1S/C4H6O/c1-2-3-4-5/h2-4H,1H3 Copy

  
• IUPAC Standard InChIKey: MLUCVPSAIODCQM-UHFFFAOYSA-N Copy
• CAS Registry Number: 4170-30-3
• 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.
• Stereoisomers:
  • 2-Butenal, (E)-
  • 2-Butenal, (Z)-
• Other names: Crotonaldehyde; Crotonal; Crotonic aldehyde; Crotylaldehyde; β-Methylacrolein; Propylene aldehyde; Krotonaldehyd; Rcra waste number U053; UN 1143; But-2-enal; 1-Formylpropene; 2-Butenaldehyde; NSC 56354
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• Information on this page:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.

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

C₄H₅O^- +  =

By formula: C₄H₅O^- + H⁺ = C₄H₆O

(CAS Reg. No. 64724-02-3 • 4294967295) +  = CAS Reg. No. 64724-02-3

By formula: (CAS Reg. No. 64724-02-3 • 4294967295C₄H₆O) + C₄H₆O = CAS Reg. No. 64724-02-3

 +  =

By formula: H₂ + C₄H₆O = C₄H₈O

 +  =  + 2

By formula: C₆H₁₂O₂ + H₂O = C₄H₆O + 2CH₄O

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

Data compiled as indicated in comments:
B - John E. Bartmess
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 C₄H₆O⁺ (ion structure unspecified)

Ionization energy determinations

De-protonation reactions

C₄H₅O^- +  =

By formula: C₄H₅O^- + H⁺ = C₄H₆O

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, Eugeny B. Stern, Antonina A. Goncharova, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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Additional Data

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, Notes

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

Van-chin-syan, Kochubei, et al., 1996
Van-chin-syan, Yu.Ya.; Kochubei, V.V.; Sergeev, V.V.; Raevskii, Yu.A.; Gerasimchuk, S.I.; Kotovich, Kh.Z., Thermodynamic properties of some acids and aldehydes of the acrylic series, Sov. J. Chem. Phys. (Engl. Transl.), 1996, 70, 1789-1794, In original 1932. [all data]

Tjebbes, 1960
Tjebbes, J., Heats of combustion of butannal and some related compounds, Acta Chem. Scand., 1960, 14, 180-188. [all data]

Dolliver, Gresham, et al., 1938
Dolliver, M.A.; Gresham, T.L.; Kistiakowsky, G.B.; Smith, E.A.; Vaughan, W.E., Heats of organic reactions. VI. Heats of hydrogenation of some oxygen-containing compounds, J. Am. Chem. Soc., 1938, 60, 440-450. [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]

Bartmess and Kiplinger, 1986
Bartmess, J.E.; Kiplinger, J.P., 'Kinetic' vs. thermodynamic acidities of enones in the gas phase, J. Org. Chem., 1986, 51, 2173. [all data]

Alconcel, Deyerl, et al., 2001
Alconcel, L.S.; Deyerl, H.J.; Continetti, R.E., Effects of alkyl substitution on the energetics of enolate anions and radicals, J. Am. Chem. Soc., 2001, 123, 50, 12675-12681, https://doi.org/10.1021/ja0120431 . [all data]

Zimmerman, Reed, et al., 1977
Zimmerman, A.H.; Reed, K.J.; Brauman, J.I., Photodetachment of electrons from enolate anions. Gas phase electron affinities of enolate radicals, J. Am. Chem. Soc., 1977, 99, 7203. [all data]

Wiberg, Morgan, et al., 1994
Wiberg, K.B.; Morgan, K.M.; Maltz, H., Thermochemistry of carbonyl reactions. 6. A study of hydration equilibria, J. Am. Chem. Soc., 1994, 116, 11067-11077. [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]

Masclet and Mouvier, 1978
Masclet, P.; Mouvier, G., Etude par spectrometrie photoelectronique d'aldehydes et de cetones ethyleniques conjugues, J. Electron Spectrosc. Relat. Phenom., 1978, 14, 77. [all data]

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

Klessinger and Gunkel, 1978
Klessinger, M.; Gunkel, E., The electronic structure of polyenes and unsaturated carbonyl compounds, Tetrahedron, 1978, 34, 3591. [all data]

Blacet, 1948
Blacet, F.E., The photochemistry of the aldehydes, J. Phys. Chem., 1948, 52, 534-545. [all data]

Notes

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• Symbols used in this document:
  

  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

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