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
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Options:
Data at NIST subscription sites:
NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.
Phase change data
Go To: Top, 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 |
Gas phase ion energetics data
Go To: Top, Phase change 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, 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]
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]
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]
Notes
Go To: Top, Phase change 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
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.