Benzoic acid, 2-methyl-
- Formula: C8H8O2
- Molecular weight: 136.1479
- IUPAC Standard InChIKey: ZWLPBLYKEWSWPD-UHFFFAOYSA-N
- CAS Registry Number: 118-90-1
- 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: o-Toluic acid; o-Methylbenzoic acid; o-Toluylic acid; 2-Methylbenzoic acid; Orthotoluic acid
- 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.
Gas phase thermochemistry 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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -320.6 ± 1.5 | kJ/mol | Ccb | Colomina, Jimenez, et al., 1986 | see Colomina, Boned, et al., 1961 and Colomina, Perez Ossorio, et al., 1959; ALS |
ΔfH°gas | -320.6 | kJ/mol | N/A | Corral, 1960 | Value computed using ΔfHsolid° value of -416.5±0.9 kj/mol from Corral, 1960 and ΔsubH° value of 95.9 kj/mol from Colomina, Jimenez, et al., 1986.; DRB |
ΔfH°gas | -331.2 | kJ/mol | N/A | Breitenbach and Derkosch, 1951 | Value computed using ΔfHsolid° value of -427.1±3.8 kj/mol from Breitenbach and Derkosch, 1951 and ΔsubH° value of 95.9 kj/mol from Colomina, Jimenez, et al., 1986.; DRB |
Reaction thermochemistry data
Go To: Top, Gas phase 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: 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
C8H7O2- + =
By formula: C8H7O2- + H+ = C8H8O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1419. ± 9.2 | kJ/mol | G+TS | Kebarle and McMahon, 1977 | gas phase |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1390. ± 8.4 | kJ/mol | IMRE | Kebarle and McMahon, 1977 | gas phase |
ΔrG° | 1391. ± 8.4 | kJ/mol | IMRE | Decouzon, Ertl, et al., 1993 | gas phase |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry 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 evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
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 C8H8O2+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Proton affinity (review) | 838.8 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 807.8 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.1 | PE | Meeks, Wahlborg, et al., 1981 | LLK |
9.4 | PE | Meeks, Wahlborg, et al., 1981 | Vertical value; LLK |
De-protonation reactions
C8H7O2- + =
By formula: C8H7O2- + H+ = C8H8O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1419. ± 9.2 | kJ/mol | G+TS | Kebarle and McMahon, 1977 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1390. ± 8.4 | kJ/mol | IMRE | Kebarle and McMahon, 1977 | gas phase; B |
ΔrG° | 1391. ± 8.4 | kJ/mol | IMRE | Decouzon, Ertl, et al., 1993 | gas phase; B |
References
Go To: Top, Gas phase thermochemistry 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.
Colomina, Jimenez, et al., 1986
Colomina, M.; Jimenez, P.; Roux, M.V.; Turrion, C.,
Propiedades termoquimicas de derivados del acido benzoico. XIII. Presiones de vapor y entalpias de sublimacion y formacion de los acidos toluicos,
An. Quim., 1986, 82, 126-130. [all data]
Colomina, Boned, et al., 1961
Colomina, M.; Boned, M.L.; Turrion, C.,
Investigaciones termoquimicas sobre los acidos alquilbenzoicos. I. Acidos toluicos,
An. Fis. Quim., 1961, 57, 655-664. [all data]
Colomina, Perez Ossorio, et al., 1959
Colomina, M.; Perez Ossorio, R.; Boned, M.L.; Panea, M.; Turrion, C.,
Thermochemical investigations on methylsubstituted benzoic acids, Rpt. for the U.S. Dept. of the Army, European Research Office contract no. DA-91-508-EUC-358 by Instituto de Quimica Fisica Madrid, Spain, 1959, 1-36. [all data]
Corral, 1960
Corral, L.B.,
Investigaciones termoquimicas sobre los acidos toluicos y dimetilbenzoicos,
Rev. R. Acad. Cienc., 1960, 54, 365-403. [all data]
Breitenbach and Derkosch, 1951
Breitenbach, J.W.; Derkosch, J.,
Verbrennungswarmen von peroxyden und verwandten verbindungen sowie von polystrolen,
Monatsh. Chem., 1951, 82, 177-179. [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]
Decouzon, Ertl, et al., 1993
Decouzon, M.; Ertl, P.; Exner, O.; Gal, J.F.; Maria, P.C.,
Concepts of Sterically Hindered Resonance and Buttressing Effect - Gas-Phase Acidities of Methyl-Substituted Benzoic Acids and Basicities of,
J. Am. Chem. Soc., 1993, 115, 25, 12071, https://doi.org/10.1021/ja00078a052
. [all data]
Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G.,
Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update,
J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018
. [all data]
Meeks, Wahlborg, et al., 1981
Meeks, J.; Wahlborg, A.; McGlynn, S.P.,
Photoelectron spectroscopy of carbonyls: Benzoic acid and its derivatives,
J. Electron Spectrosc. Relat. Phenom., 1981, 22, 43. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
ΔfH°gas Enthalpy of formation of gas at standard conditions 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
- 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.