CH2=CHO anion
- Formula: C2H3O-
- Molecular weight: 43.0452
- CAS Registry Number: 35731-40-9
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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 compiled by: John E. Bartmess
Protonation reactions
By formula: C2H3O- + H+ = C2H4O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 366.42 ± 0.81 | kcal/mol | D-EA | Mead, Lykke, et al., 1984 | gas phase; Uncertainty: 6 millical/mol (0.26 micro-eV).Dipolebound state at ca. 14.3 cal/mol (5 cm-1) |
ΔrH° | 365.8 ± 2.2 | kcal/mol | G+TS | Bartmess, Scott, et al., 1979 | gas phase; Acid: ethanal. The enol is 9.6 kcal/mol more acidic: Holmes and Lossing, 1982; value altered from reference due to change in acidity scale |
ΔrH° | 366.5 ± 2.9 | kcal/mol | G+TS | Cumming and Kebarle, 1978 | gas phase |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 359.6 ± 1.2 | kcal/mol | H-TS | Mead, Lykke, et al., 1984 | gas phase; Uncertainty: 6 millical/mol (0.26 micro-eV).Dipolebound state at ca. 14.3 cal/mol (5 cm-1) |
ΔrG° | 359.0 ± 2.0 | kcal/mol | IMRE | Bartmess, Scott, et al., 1979 | gas phase; Acid: ethanal. The enol is 9.6 kcal/mol more acidic: Holmes and Lossing, 1982; value altered from reference due to change in acidity scale |
ΔrG° | 359.7 ± 2.0 | kcal/mol | IMRE | Cumming and Kebarle, 1978 | gas phase |
References
Go To: Top, 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.
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]
Notes
Go To: Top, Gas phase ion energetics data, References
- Symbols used in this document:
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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