Gentisic acid
- Formula: C5H11NO2
- Molecular weight: 117.1463
- IUPAC Standard InChI: InChI=1S/C7H6O4/c8-4-1-2-6(9)5(3-4)7(10)11/h1-3,8-9H,(H,10,11)
- IUPAC Standard InChIKey: WXTMDXOMEHJXQO-UHFFFAOYSA-N
- CAS Registry Number: 490-79-9
- 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, 2,5-dihydroxy-; Gensigen; Gensigon; Hydroquinonecarboxylic acid; 2,5-Dihydroxybenzoic acid; 2,5-Dioxybenzoic acid; 5-Hydroxysalicylic acid; Gentisate; Salicylic acid, 5-hydroxy-; 2,5-Dhba; Kyselina 2,5-dihydroxybenzoova; Kyselina gentisinova; 3,6-Dihydroxybenzoic acid; Gentisinic acid; NSC 27224
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Phase change data
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, 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: William E. Acree, Jr., James S. Chickos
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔsubH° | 130.4 ± 1.3 | kJ/mol | ME | Monte, Gonc«807»alves, et al., 2010 | Based on data from 372. to 389. K. |
Enthalpy of sublimation
| ΔsubH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 128.1 ± 1.4 | 380. | ME | Monte, Gonc«807»alves, et al., 2010 | Based on data from 372. to 389. K. |
| 117.9 ± 1.4 | 370. | N/A | Chen, Oja, et al., 2006 | Based on data from 362. to 379. K. |
Enthalpy of fusion
| ΔfusH (kJ/mol) | Temperature (K) | Method | Reference |
|---|---|---|---|
| 20.8 | 476.2 | DSC | Monte, Gonc«807»alves, et al., 2010 |
Reaction thermochemistry data
Go To: Top, Phase change data, Gas phase ion energetics data, 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
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
C7H5O4- + =
By formula: C7H5O4- + H+ = C5H11NO2
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrG° | 1329. ± 11. | kJ/mol | IMRB | Breuker, Knochenmuss, et al., 1999 | gas phase; Acid: 2,5-dihydroxy benzoic acid |
Gas phase ion energetics data
Go To: Top, Phase change data, Reaction thermochemistry data, References, Notes
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
MM - Michael M. Meot-Ner (Mautner)
Proton affinity at 298K
| Proton affinity (kJ/mol) | Reference | Comment |
|---|---|---|
| 531.6 ± 1.3 | Kuo, Zhang, et al., 1997 | T = 298K; Photoionization of HNO yields DHf(HNO+) from which PA(NO) is calculated at 0 K and 298K.; MM |
De-protonation reactions
C7H5O4- + =
By formula: C7H5O4- + H+ = C5H11NO2
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrG° | 1329. ± 11. | kJ/mol | IMRB | Breuker, Knochenmuss, et al., 1999 | gas phase; Acid: 2,5-dihydroxy benzoic acid; B |
References
Go To: Top, Phase change data, Reaction thermochemistry data, 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.
Monte, Gonc«807»alves, et al., 2010
Monte, Manuel J.S.; Gonc«807»alves, Mariana V.; Ribeiro da Silva, Maria D.M.C.,
Vapor Pressures and Enthalpies of Combustion of the Dihydroxybenzoic Acid Isomers,
J. Chem. Eng. Data, 2010, 55, 6, 2246-2251, https://doi.org/10.1021/je900777q
. [all data]
Chen, Oja, et al., 2006
Chen, Xu; Oja, Vahur; Chan, W. Geoffrey; Hajaligol, Mohammad R.,
Vapor Pressure Characterization of Several Phenolics and Polyhydric Compounds by Knudsen Effusion Method,
J. Chem. Eng. Data, 2006, 51, 2, 386-391, https://doi.org/10.1021/je050293h
. [all data]
Breuker, Knochenmuss, et al., 1999
Breuker, K.; Knochenmuss, R.; Zenobi, R.,
Gas-phase basicities of deprotonated matrix-assisted laser desorption/ionization matrix molecules,
Int. J. Mass Spectrom., 1999, 184, 1, 25-38, https://doi.org/10.1016/S1387-3806(98)14200-8
. [all data]
Kuo, Zhang, et al., 1997
Kuo, S.C.; Zhang, Z.Y.; Ross, S.K.; Klemm, R.B.; Johnson, R.D.; Monks, P.S.; Thorn, R.P.; Stief, L.J.,
Discharge flow-photoionization mass spectrometric study of HNO: Phtoionization efficiency spectrum and ionization energy and proton affinity of NO,
J. Phys. Chem. A, 1997, 101, 4035. [all data]
Notes
Go To: Top, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
ΔfusH Enthalpy of fusion ΔrG° Free energy of reaction at standard conditions ΔsubH Enthalpy of sublimation ΔsubH° Enthalpy of sublimation at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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