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
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Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, 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 |
Condensed phase thermochemistry 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°solid | -416.5 ± 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°solid | -416.5 ± 0.92 | kJ/mol | Ccb | Corral, 1960 | ALS |
ΔfH°solid | -427.1 ± 3.8 | kJ/mol | Ccb | Breitenbach and Derkosch, 1951 | Reanalyzed by Cox and Pilcher, 1970, Original value = -426.3 kJ/mol; ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -3874.9 ± 0.8 | kJ/mol | Ccb | Colomina, Jimenez, et al., 1986 | see Colomina, Boned, et al., 1961 and Colomina, Perez Ossorio, et al., 1959; Corresponding ΔfHºsolid = -416.5 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°solid | -3874.4 ± 4.6 | kJ/mol | Ccb | Holdiness, 1983 | Corresponding ΔfHºsolid = -417.0 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°solid | -3875.0 ± 0.75 | kJ/mol | Ccb | Corral, 1960 | Corresponding ΔfHºsolid = -416.4 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°solid | -3864. | kJ/mol | Ccb | Breitenbach and Derkosch, 1951 | Corresponding ΔfHºsolid = -427.2 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°solid | -3858. | kJ/mol | Ccb | Auwers and Roth, 1910 | Corresponding ΔfHºsolid = -433.9 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Constant pressure heat capacity of solid
Cp,solid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
174.9 | 298. | Andrews, Lynn, et al., 1926 | T = 22 to 200 C.; DH |
Reaction thermochemistry 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 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
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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 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, Condensed 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]
Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G.,
Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]
Holdiness, 1983
Holdiness, M.R.,
Heats of atomization and resonance energy of some ortho-substituted benzoic acids,
Thermochim. Acta, 1983, 71, 257-263. [all data]
Auwers and Roth, 1910
Auwers, K.; Roth, W.A.,
Thermochemische Untersuchungen. I. Uber Beziehungen zwischen Konstitution und Verbrennungswarme ungesattigter Verbindungen,
Justus Liebigs Ann. Chem., 1910, 239-248. [all data]
Andrews, Lynn, et al., 1926
Andrews, D.H.; Lynn, G.; Johnston, J.,
The heat capacities and heat of crystallization of some isomeric aromatic compounds,
J. Am. Chem. Soc., 1926, 48, 1274-1287. [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, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
Cp,solid Constant pressure heat capacity of solid ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°solid Enthalpy of formation of solid 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
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