MeCO2 anion
- Formula: C2H3O2-
- Molecular weight: 59.0446
- IUPAC Standard InChIKey: QTBSBXVTEAMEQO-UHFFFAOYSA-M
- CAS Registry Number: 71-50-1
- Chemical structure:
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Gas phase ion energetics data
Go To: Top, 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: John E. Bartmess
Electron affinity of neutral species
EAneutral (eV) | Method | Reference | Comment |
---|---|---|---|
3.250 ± 0.010 | LPES | Wang, Woo, et al., 2006 | At 20 K |
3.380 ± 0.050 | LPES | Wang, Jagoda-Cwiklik, et al., 2009 | |
<3.470 ± 0.010 | LPES | Lu and Continetti, 2004 | EA is upper limit, though close |
3.40 ± 0.30 | LPES | Ding, Wang, et al., 1998 | Around 3.4 eV" for CH3(CH2)nCO2-, n=0-8, Dervived DH = 113.4±8 kcal/mol |
3.179 ± 0.052 | ECD | Wentworth, Chen, et al., 1968 | Data reworked with current bond strengths |
3.30 ± 0.20 | EIAE | Tsuda and Hamill, 1964 | From MeCO2Et |
Protonation reactions
By formula: C2H3O2- + H+ = C2H4O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1457. ± 5.9 | kJ/mol | CIDC | Angel and Ervin, 2006 | gas phase |
ΔrH° | 1456. ± 9.2 | kJ/mol | G+TS | Taft and Topsom, 1987 | gas phase |
ΔrH° | 1459. ± 8.8 | kJ/mol | G+TS | Cumming and Kebarle, 1978 | gas phase |
ΔrH° | 1459. ± 9.2 | kJ/mol | G+TS | Fujio, McIver, et al., 1981 | gas phase; value altered from reference due to change in acidity scale |
ΔrH° | 1435.9 ± 2.9 | kJ/mol | EIAE | Muftakhov, Vasil'ev, et al., 1999 | gas phase |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1427. ± 8.4 | kJ/mol | IMRE | Taft and Topsom, 1987 | gas phase |
ΔrG° | 1429. ± 8.4 | kJ/mol | IMRE | Cumming and Kebarle, 1978 | gas phase |
ΔrG° | 1430. ± 8.4 | kJ/mol | IMRE | Fujio, McIver, et al., 1981 | gas phase; value altered from reference due to change in acidity scale |
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.
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]
Notes
Go To: Top, Gas phase ion energetics data, References
- Symbols used in this document:
EAneutral Electron affinity of neutral species 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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