p-Cresol
- Formula: C7H8O
- Molecular weight: 108.1378
- IUPAC Standard InChIKey: IWDCLRJOBJJRNH-UHFFFAOYSA-N
- CAS Registry Number: 106-44-5
- 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: Phenol, 4-methyl-; p-Hydroxytoluene; p-Kresol; p-Methylhydroxybenzene; p-Methylphenol; p-Oxytoluene; p-Toluol; p-Tolyl alcohol; 1-Hydroxy-4-methylbenzene; 4-Cresol; 4-Hydroxytoluene; 4-Methylphenol; 1-Methyl-4-hydroxybenzene; Paracresol; Cresol, para; Paramethyl phenol; Rcra waste number U052; p-Cresylic acid; Cresol,p-; Phenol, 4-methyI; NSC 3696; 4-methylphenol ( p-cresol); p-Cresol (4-methylphenol)
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Gas phase ion energetics data
Go To: Top, 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:
L - Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
View reactions leading to C7H8O+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 8.34 ± 0.03 | eV | N/A | N/A | L |
Proton affinity at 298K
Proton affinity (kJ/mol) | Reference | Comment |
---|---|---|
814. ± 8. | van Beelen, Koblenz, et al., 2004 | T = 298K; PA derived by authors from GB with protonation entropy equated to Rlnσ(B)/σ(BH+); MM |
Gas basicity at 298K
Gas basicity (review) (kJ/mol) | Reference | Comment |
---|---|---|
782. ± 8. | van Beelen, Koblenz, et al., 2004 | T = 298K; PA derived by authors from GB with protonation entropy equated to Rlnσ(B)/σ(BH+); MM |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
8.31 ± 0.08 | EI | Selim, Fahmey, et al., 1991 | LL |
8.13 | EI | Russell, Freiser, et al., 1983 | LBLHLM |
8.34 | EI | Johnstone and Mellon, 1973 | LLK |
8.97 | EI | Crable and Kearns, 1962 | RDSH |
8.35 | PE | Palmer, Moyes, et al., 1979 | Vertical value; LLK |
8.38 | PE | Kobayashi and Nagakura, 1974 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C6H5+ | 15.69 ± 0.08 | ? | EI | Selim, Fahmey, et al., 1990 | LL |
C6H7+ | 11.50 | ? | EI | Russell, Freiser, et al., 1983 | LBLHLM |
C7H7+ | 11.67 ± 0.08 | OH | EI | Selim, Fahmey, et al., 1990 | LL |
C7H7O+ | 11.13 | H | EI | Russell, Freiser, et al., 1983 | LBLHLM |
C7H7O+ | 12.4 ± 0.1 | H | EI | Tait, Shannon, et al., 1962 | RDSH |
De-protonation reactions
C7H7O- + =
By formula: C7H7O- + H+ = C7H8O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1465. ± 8.8 | kJ/mol | G+TS | Fujio, McIver, et al., 1981 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrH° | 1465. ± 8.8 | kJ/mol | G+TS | Bartmess, Scott, et al., 1979 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrH° | 1471. ± 9.6 | kJ/mol | G+TS | Kebarle and McMahon, 1977 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1437. ± 8.4 | kJ/mol | IMRE | Fujio, McIver, et al., 1981 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrG° | 1437. ± 8.4 | kJ/mol | IMRE | Bartmess, Scott, et al., 1979 | gas phase; value altered from reference due to change in acidity scale; B |
ΔrG° | 1442. ± 8.4 | kJ/mol | IMRE | Kebarle and McMahon, 1977 | gas phase; B |
References
Go To: Top, 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.
van Beelen, Koblenz, et al., 2004
van Beelen, E.S.E.; Koblenz, T.A.; Ingemann, S.; Hammerum, S.,
Experimental and theoretical evaluation of proton affinities of furan, the methylphenols, and the related anisoles,
J. Phys. Chem. A, 2004, 108, 2787. [all data]
Selim, Fahmey, et al., 1991
Selim, E.T.M.; Fahmey, M.A.; Ghonime, H.S.,
Mass spectrometric study of molecular ions of methyl-phenol isomers using electron impact technique,
Indian J. Phys., 1991, 65, 171. [all data]
Russell, Freiser, et al., 1983
Russell, D.H.; Freiser, B.S.; McBay, E.H.; Canada, D.C.,
The structure of decomposing [C7H7O]+ ions: Benzyl versus tropylium ion structures,
Org. Mass Spectrom., 1983, 18, 474. [all data]
Johnstone and Mellon, 1973
Johnstone, R.A.W.; Mellon, F.A.,
Effects of induction and resonance in the calculation of ionization potentials of substituted benzenes by perturbation molecular orbital theory,
J. Chem. Soc. Faraday Trans. 2, 1973, 69, 36. [all data]
Crable and Kearns, 1962
Crable, G.F.; Kearns, G.L.,
Effect of substituent groups on the ionization potentials of benzenes,
J. Phys. Chem., 1962, 66, 436. [all data]
Palmer, Moyes, et al., 1979
Palmer, M.H.; Moyes, W.; Speirs, M.; Ridyard, J.N.A.,
The electronic structure of substituted benzenes; ab initio calculations and photoelectron spectra for phenol, the methyl- and fluoro-derivatives, and the dihydroxybenzenes,
J. Mol. Struct., 1979, 52, 293. [all data]
Kobayashi and Nagakura, 1974
Kobayashi, T.; Nagakura, S.,
Photoelectron spectra of substituted benzenes,
Bull. Chem. Soc. Jpn., 1974, 47, 2563. [all data]
Selim, Fahmey, et al., 1990
Selim, E.T.M.; Fahmey, M.A.; Ghonime, H.S.,
[C7H7]+ and [C6H5]+ fragment ions produced from methylphenol isomers by electron impact,
Org. Mass Spectrom., 1990, 26, 55. [all data]
Tait, Shannon, et al., 1962
Tait, J.M.S.; Shannon, T.W.; Harrison, A.G.,
The structure of substituted C7 ions from benzyl derivatives at the appearance potential threshold,
J. Am. Chem. Soc., 1962, 84, 4. [all data]
Fujio, McIver, et al., 1981
Fujio, M.; McIver, R.T., Jr.; Taft, R.W.,
Effects on the acidities of phenols from specific substituent-solvent interactions. Inherent substituent parameters from gas phase acidities,
J. Am. Chem. Soc., 1981, 103, 4017. [all data]
Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr.,
The gas phase acidity scale from methanol to phenol,
J. Am. Chem. Soc., 1979, 101, 6047. [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]
Notes
Go To: Top, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization 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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