Benzoic acid, 3-methyl-
- Formula: C8H8O2
- Molecular weight: 136.1479
- IUPAC Standard InChIKey: GPSDUZXPYCFOSQ-UHFFFAOYSA-N
- CAS Registry Number: 99-04-7
- 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: m-Toluic acid; m-Methylbenzoic acid; m-Toluylic acid; 3-Methylbenzoic acid; meta-Toluic acid
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Phase change data
Go To: Top, Gas phase ion energetics data, Gas Chromatography, 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 536.2 | K | N/A | Aldrich Chemical Company Inc., 1990 | BS |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 384. | K | N/A | Sugunan and Thomas, 1993 | Uncertainty assigned by TRC = 1.5 K; TRC |
Tfus | 384.4 | K | N/A | Noyce and Nagle, 1953 | Uncertainty assigned by TRC = 2. K; TRC |
Tfus | 381.9 | K | N/A | Andrews, Lynn, et al., 1926 | Uncertainty assigned by TRC = 0.2 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔsubH° | 97.0 ± 0.3 | kJ/mol | ME | Colomina, Jimenez, et al., 1986 | Based on data from 303. to 323. K.; AC |
ΔsubH° | 97.0 ± 0.3 | kJ/mol | V | Colomina, Jimenez, et al., 1986, 2 | see Colomina, Boned, et al., 1961; ALS |
ΔsubH° | 97.0 | kJ/mol | N/A | Colomina, Jimenez, et al., 1986, 2 | DRB |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
62.8 | 503. | A | Stephenson and Malanowski, 1987 | Based on data from 473. to 533. K. See also Mullayanov, Galagan, et al., 1970.; AC |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
15.73 | 381.9 | Acree, 1991 | AC |
15.730 | 381.9 | Andrews, Lynn, et al., 1926, 2 | DH |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
41.2 | 381.9 | Andrews, Lynn, et al., 1926, 2 | DH |
Gas phase ion energetics data
Go To: Top, Phase change data, Gas Chromatography, 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) | 829.8 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 798.8 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.4 ± 0.2 | EI | Benoit, 1973 | LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C7H7+ | 12.5 ± 0.2 | COOH | EI | Benoit, 1973 | LLK |
C8H7O+ | 12.4 ± 0.2 | OH | EI | Benoit, 1973 | LLK |
De-protonation reactions
C8H7O2- + =
By formula: C8H7O2- + H+ = C8H8O2
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1425. ± 8.8 | kJ/mol | G+TS | Kebarle and McMahon, 1977 | gas phase; B |
ΔrH° | 1424. ± 8.8 | kJ/mol | G+TS | Decouzon, Exner, et al., 1996 | gas phase; Relative to benzoate at 333.0 kcal/mol; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1396. ± 8.4 | kJ/mol | IMRE | Kebarle and McMahon, 1977 | gas phase; B |
ΔrG° | 1395. ± 8.4 | kJ/mol | IMRE | Decouzon, Exner, et al., 1996 | gas phase; Relative to benzoate at 333.0 kcal/mol; B |
Gas Chromatography
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: NIST Mass Spectrometry Data Center, William E. Wallace, director
Normal alkane RI, non-polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | Ultra-1 | 1249. | Okumura, 1991 | 25. m/0.32 mm/0.25 μm, He, 3. K/min; Tstart: 80. C; Tend: 260. C |
Normal alkane RI, non-polar column, custom temperature program
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | HP-5MS | 1325. | Alissandrakis, Kibaris, et al., 2005 | 30. m/0.25 mm/0.25 μm, He; Program: 40C(3min) => 2C/min => 180C => 10C/min => 250C(5min) |
References
Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Aldrich Chemical Company Inc., 1990
Aldrich Chemical Company Inc.,
Catalog Handbook of Fine Chemicals, Aldrich Chemical Company, Inc., Milwaukee WI, 1990, 1. [all data]
Sugunan and Thomas, 1993
Sugunan, S.; Thomas, B.,
Salting Coefficients of 2-, 3-, and 4-Methylbenzoic Acids,
J. Chem. Eng. Data, 1993, 38, 520-1. [all data]
Noyce and Nagle, 1953
Noyce, D.S.; Nagle, R.J.,
Studies of Configuration II. The Configurations of the 3-Methylcyclohexylamines,
J. Am. Chem. Soc., 1953, 75, 127. [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. [all data]
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. [all data]
Colomina, Jimenez, et al., 1986, 2
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]
Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw,
Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2
. [all data]
Mullayanov, Galagan, et al., 1970
Mullayanov, F.I.; Galagan, G.V.; Buz'ko, M.F.; Churkin, Yu.V.; Shiryaeva, A.A.,
Tr. Nauch. Issled. Inst. Neftekhim. Proizvod., 1970, 2, 95. [all data]
Acree, 1991
Acree, William E.,
Thermodynamic properties of organic compounds: enthalpy of fusion and melting point temperature compilation,
Thermochimica Acta, 1991, 189, 1, 37-56, https://doi.org/10.1016/0040-6031(91)87098-H
. [all data]
Andrews, Lynn, et al., 1926, 2
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]
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]
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]
Decouzon, Exner, et al., 1996
Decouzon, M.; Exner, O.; Gal, J.-F.; Maria, P.-C.,
Non-classical Buttressing Effect: Gas-phase Ionization of Some Methyl Substituted Benzoic Acids,
J. Chem. Soc. Perkin Trans., 1996, 2, 4, 475, https://doi.org/10.1039/p29960000475
. [all data]
Okumura, 1991
Okumura, T.,
retention indices of environmental chemicals on methyl silicone capillary column,
Journal of Environmental Chemistry (Japan), 1991, 1, 2, 333-358, https://doi.org/10.5985/jec.1.333
. [all data]
Alissandrakis, Kibaris, et al., 2005
Alissandrakis, E.; Kibaris, A.C.; Tarantilis, P.A.; Harizanis, P.C.; Polissiou, M.,
Flavour compounds of Greek cotton honey,
J. Sci. Food Agric., 2005, 85, 9, 1444-1452, https://doi.org/10.1002/jsfa.2124
. [all data]
Notes
Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, References
- Symbols used in this document:
AE Appearance energy Tboil Boiling point Tfus Fusion (melting) point ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔsubH° Enthalpy of sublimation at standard conditions ΔvapH Enthalpy of vaporization - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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