Benzoic acid, 4-hydroxy-
- Formula: C7H6O3
- Molecular weight: 138.1207
- IUPAC Standard InChI: InChI=1S/C7H6O3/c8-6-3-1-5(2-4-6)7(9)10/h1-4,8H,(H,9,10)
- IUPAC Standard InChIKey: FJKROLUGYXJWQN-UHFFFAOYSA-N
- CAS Registry Number: 99-96-7
- 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. - Other names: Benzoic acid, p-hydroxy-; p-Hydroxybenzoic acid; p-Salicylic acid; Paraben-acid; 4-Carboxyphenol; 4-Hydroxybenzoic acid; para-Hydroxybenzoic acid; Hydroxybenzoic acid, para; Kyselina 4-hydroxybenzoova; NSC 4961; Paraben
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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 as indicated in comments:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
View reactions leading to C7H6O3+ (ion structure unspecified)
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 9.2 ± 0.2 | EI | Benoit, 1973 | LLK |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| C6H5O+ | 14.6 ± 0.2 | CO+OH | EI | Benoit, 1973 | LLK |
| C7H5O2+ | 12.0 ± 0.2 | OH | EI | Benoit, 1973 | LLK |
De-protonation reactions
C7H5O3- + =
By formula: C7H5O3- + H+ = C7H6O3
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 335.9 ± 2.1 | kcal/mol | G+TS | Kebarle and McMahon, 1977 | gas phase; This is probably the phenolic site acidity, not the carboxylic.; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 328.9 ± 2.0 | kcal/mol | IMRE | Kebarle and McMahon, 1977 | gas phase; This is probably the phenolic site acidity, not the carboxylic.; B |
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.
Benoit, 1973
Benoit, F.,
Substituent effects in mass spectrometry. III. Substituent effects in the dissociation of the molecular ions of para and meta subtituted benzoic acids,
Org. Mass Spectrom., 1973, 7, 295. [all data]
Kebarle and McMahon, 1977
Kebarle, P.; McMahon, T.B.,
Intrinsic Acidities of Substituted Phenols and Benzoic Acids Determined by Gas Phase Proton Transfer Equilibria,
J. Am. Chem. Soc., 1977, 99, 7, 2222, https://doi.org/10.1021/ja00449a032
. [all data]
Notes
Go To: Top, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy 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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