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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Gas phase ion energetics data
Go To: Top, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, 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) | 198.3 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 190.9 | kcal/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° | 340.6 ± 2.1 | kcal/mol | G+TS | Kebarle and McMahon, 1977 | gas phase; B |
ΔrH° | 340.4 ± 2.1 | kcal/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° | 333.6 ± 2.0 | kcal/mol | IMRE | Kebarle and McMahon, 1977 | gas phase; B |
ΔrG° | 333.4 ± 2.0 | kcal/mol | IMRE | Decouzon, Exner, et al., 1996 | gas phase; Relative to benzoate at 333.0 kcal/mol; B |
IR Spectrum
Go To: Top, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Gas Phase Spectrum
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Notice: Concentration information is not available for this spectrum and, therefore, molar absorptivity values cannot be derived.
Additional Data
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Owner | NIST Standard Reference Data Program Collection (C) 2018 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | Sadtler Research Labs Under US-EPA Contract |
State | gas |
Mass spectrum (electron ionization)
Go To: Top, Gas phase ion energetics data, IR Spectrum, UV/Visible spectrum, 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
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Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | NIST Mass Spectrometry Data Center, 1998. |
NIST MS number | 291073 |
UV/Visible spectrum
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Spectrum
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Additional Data
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Source | Lang (editor), 1969 |
---|---|
Owner | INEP CP RAS, NIST OSRD Collection (C) 2007 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
Origin | INSTITUTE OF ENERGY PROBLEMS OF CHEMICAL PHYSICS, RAS |
Source reference | RAS UV No. 19062 |
Instrument | Unicam SP 700 |
Melting point | 110-111 |
Gas Chromatography
Go To: Top, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, 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, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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]
Lang (editor), 1969
Lang (editor), L.,
Absorption Spectra in the Ultraviolet and Visible Region, 1969, 12, 63. [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, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, References
- Symbols used in this document:
AE Appearance energy 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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