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MeCO2 anion

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

Electron affinity of neutral species

EAneutral (eV) Method Reference Comment
3.250 ± 0.010LPESWang, Woo, et al., 2006At 20 K
3.380 ± 0.050LPESWang, Jagoda-Cwiklik, et al., 2009 
<3.470 ± 0.010LPESLu and Continetti, 2004EA is upper limit, though close
3.40 ± 0.30LPESDing, Wang, et al., 1998Around 3.4 eV" for CH3(CH2)nCO2-, n=0-8, Dervived DH = 113.4±8 kcal/mol
3.179 ± 0.052ECDWentworth, Chen, et al., 1968Data reworked with current bond strengths
3.30 ± 0.20EIAETsuda and Hamill, 1964From MeCO2Et

Protonation reactions

MeCO2 anion + Hydrogen cation = Acetic acid

By formula: C2H3O2- + H+ = C2H4O2

Quantity Value Units Method Reference Comment
Deltar348.2 ± 1.4kcal/molCIDCAngel and Ervin, 2006gas phase
Deltar348.1 ± 2.2kcal/molG+TSTaft and Topsom, 1987gas phase
Deltar348.6 ± 2.1kcal/molG+TSCumming and Kebarle, 1978gas phase
Deltar348.7 ± 2.2kcal/molG+TSFujio, McIver, et al., 1981gas phase; value altered from reference due to change in acidity scale
Deltar343.20 ± 0.70kcal/molEIAEMuftakhov, Vasil'ev, et al., 1999gas phase
Quantity Value Units Method Reference Comment
Deltar341.1 ± 2.0kcal/molIMRETaft and Topsom, 1987gas phase
Deltar341.5 ± 2.0kcal/molIMRECumming and Kebarle, 1978gas phase
Deltar341.7 ± 2.0kcal/molIMREFujio, McIver, et al., 1981gas phase; value altered from reference due to change in acidity scale


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.

Wang, Woo, et al., 2006
Wang, X.B.; Woo, H.K.; Wang, L.S.; Minofar, B.; Jungwirth, P., Determination of the electron affinity of the acetyloxyl radical (CH3COO) by low-temperature anion photoelectron spectroscopy and ab initio calculations, J. Phys. Chem. A, 2006, 110, 15, 5047-5050, https://doi.org/10.1021/jp060138p . [all data]

Wang, Jagoda-Cwiklik, et al., 2009
Wang, X.B.; Jagoda-Cwiklik, B.; Chi, C.X.; Xing, X.P.; Zhou, M.F.; Jungwirth, P.; Wang, L.S., Microsolvation of the acetate anion [CH3CO2-(H2O)(n), n=1-3]: A photoelectron spectroscopy and ab initio computational study, Chem. Phys. Lett., 2009, 477, 1-3, 41-44, https://doi.org/10.1016/j.cplett.2009.06.074 . [all data]

Lu and Continetti, 2004
Lu, Z.; Continetti, R.E., Dynamics of the acetyloxyl radical studied by dissociative photodetachment of the acetate anion, J. Phys. Chem. A, 2004, 108, 45, 9962-9969, https://doi.org/10.1021/jp040355v . [all data]

Ding, Wang, et al., 1998
Ding, C.F.; Wang, X.B.; Wang, L.S., Photoelectron spectroscopy of doubly charged anions: Intramolecular Coulomb repulsion and solvent stabilization, J. Phys. Chem. A, 1998, 102, 45, 8633-8636, https://doi.org/10.1021/jp982698x . [all data]

Wentworth, Chen, et al., 1968
Wentworth, W.E.; Chen, E.; Steelhammer, J.C., Determination of Electron Affinities of Radicals and Bond Dissociation Energies by Electron Attachment Studies at Thermal Energies - Electron Affinity of the Acetate Radical, J. Phys. Chem., 1968, 72, 7, 2671, https://doi.org/10.1021/j100853a080 . [all data]

Tsuda and Hamill, 1964
Tsuda, S.; Hamill, W.H., Ionization Efficiency Measurements by the Retarding Potential Difference Method, Adv. Mass Spectrom., 1964, 3, 249. [all data]

Angel and Ervin, 2006
Angel, L.A.; Ervin, K.M., Gas-phase acidities and O-H bond dissociation enthalpies of phenol, 3-methylphenol, 2,4,6-trimethylphenol, and ethanoic acid, J. Phys. Chem. A, 2006, 110, 35, 10392-10403, https://doi.org/10.1021/jp0627426 . [all data]

Taft and Topsom, 1987
Taft, R.W.; Topsom, R.D., The Nature and Analysis of Substituent Effects, Prog. Phys. Org. Chem., 1987, 16, 1. [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]

Fujio, McIver, et al., 1981
Fujio, M.; McIver, R.T., Jr.; Taft, R.W., Effects on the acidities of phenols from specific substituent-solvent interactions. Inherent substituent parameters from gas phase acidities, J. Am. Chem. Soc., 1981, 103, 4017. [all data]

Muftakhov, Vasil'ev, et al., 1999
Muftakhov, M.V.; Vasil'ev, Y.V.; Mazunov, V.A., Determination of electron affinity of carbonyl radicals by means of negative ion mass spectrometry, Rapid Commun. Mass Spectrom., 1999, 13, 12, 1104-1108, https://doi.org/10.1002/(SICI)1097-0231(19990630)13:12<1104::AID-RCM619>3.0.CO;2-C . [all data]


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