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MeCOCH=C(Me)O anion


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 by: John E. Bartmess

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Individual Reactions

C5H7O2- + Hydrogen cation = Acetylacetone

By formula: C5H7O2- + H+ = C5H8O2

Quantity Value Units Method Reference Comment
Deltar1438. ± 8.8kJ/molG+TSTaft and Bordwell, 1988gas phase; at 330K: neutral enol/keto ratio should be 8:1 ( Strohmeier and Höhne, 1952)
Deltar1438. ± 9.6kJ/molG+TSCumming and Kebarle, 1978gas phase; At 500K: neutral enol/keto ratio is 1.7:1, Folkendt, Weiss-Lopez, et al., 1989. «DELTA»H=-4.7 kcal/mol, enol favored. Carbonyls anti in anion, via calc: Irikura, 1999
Quantity Value Units Method Reference Comment
Deltar1409. ± 8.4kJ/molIMRETaft and Bordwell, 1988gas phase; at 330K: neutral enol/keto ratio should be 8:1 ( Strohmeier and Höhne, 1952)
Deltar1408. ± 8.4kJ/molIMRECumming and Kebarle, 1978gas phase; At 500K: neutral enol/keto ratio is 1.7:1, Folkendt, Weiss-Lopez, et al., 1989. «DELTA»H=-4.7 kcal/mol, enol favored. Carbonyls anti in anion, via calc: Irikura, 1999

References

Go To: Top, Reaction thermochemistry data, Notes

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

Taft and Bordwell, 1988
Taft, R.W.; Bordwell, F.G., Structural and Solvent Effects Evaluated from Acidities Measured in Dimethyl Sulfoxide and in the Gas Phase, Acc. Chem. Res., 1988, 21, 12, 463, https://doi.org/10.1021/ar00156a005 . [all data]

Strohmeier and Höhne, 1952
Strohmeier, W.; Höhne, I., Keto-Enol-Umwandlung des Acetylacteons in Gaszustand, Z. Naturfor., 1952, 7B, 184. [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]

Folkendt, Weiss-Lopez, et al., 1989
Folkendt, M.M.; Weiss-Lopez, B.E.; Chauvel, J.P., Jr.; True, N.S., Gas-Phase 1H NMR Studies of Keto-Enol Tautomerization of Acetylacetone, Methyl Acetoacetate, and Ethyl Acetoacetate, J. Phys. Chem., 1989, 89, 15, 3347, https://doi.org/10.1021/j100261a038 . [all data]

Irikura, 1999
Irikura, K.K., Acetylacetonate (acac) anion in the gas phase: predicted structures, vibrational spectra, and photodetachment energies, Int. J. Mass Spectrom., 1999, 187, 577-587, https://doi.org/10.1016/S1387-3806(98)14192-1 . [all data]


Notes

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