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
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- 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, Gas phase ion energetics data, Mass spectrum (electron ionization), 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -78.37 ± 0.33 | kcal/mol | Ccb | Colomina, Jimenez, et al., 1986 | see Colomina, Boned, et al., 1961; ALS |
ΔfH°gas | -78.66 | kcal/mol | N/A | Corral, 1960 | Value computed using ΔfHsolid° value of -426.1±1.0 kj/mol from Corral, 1960 and ΔsubH° value of 97.0 kj/mol from Colomina, Jimenez, et al., 1986.; DRB |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Mass spectrum (electron ionization), 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 |
Mass spectrum (electron ionization)
Go To: Top, Gas phase thermochemistry data, 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.
Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
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 |
Gas Chromatography
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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 thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Gas Chromatography, 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]
Corral, 1960
Corral, L.B.,
Investigaciones termoquimicas sobre los acidos toluicos y dimetilbenzoicos,
Rev. R. Acad. Cienc., 1960, 54, 365-403. [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, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), Gas Chromatography, References
- Symbols used in this document:
AE Appearance energy 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.