Benzene, 1,3-dimethyl-
- Formula: C8H10
- Molecular weight: 106.1650
- IUPAC Standard InChIKey: IVSZLXZYQVIEFR-UHFFFAOYSA-N
- CAS Registry Number: 108-38-3
- 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-Xylene; m-Dimethylbenzene; m-Xylol; 1,3-Dimethylbenzene; 1,3-Xylene; 2,4-Xylene; m-Methyltoluene; meta-Xylene; NSC 61769; UN 1307; 1,3-dimethylbenzene (m-xylene)
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Reaction thermochemistry data
Go To: Top, 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:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
B - 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
By formula: C3H9Si+ + C8H10 = (C3H9Si+ • C8H10)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 121. | kJ/mol | PHPMS | Wojtyniak and Stone, 1986 | gas phase; switching reaction,Thermochemical ladder((CH3)3Si+)C6H6, Entropy change calculated or estimated; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 147. | J/mol*K | N/A | Wojtyniak and Stone, 1986 | gas phase; switching reaction,Thermochemical ladder((CH3)3Si+)C6H6, Entropy change calculated or estimated; M |
Free energy of reaction
ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
53.1 | 468. | PHPMS | Wojtyniak and Stone, 1986 | gas phase; switching reaction,Thermochemical ladder((CH3)3Si+)C6H6, Entropy change calculated or estimated; M |
By formula: C9H12+ + C8H10 = (C9H12+ • C8H10)
Bond type: Charge transfer bond (positive ion)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 59.8 | kJ/mol | PHPMS | Meot-Ner (Mautner), Hamlet, et al., 1978 | gas phase; Entropy change calculated or estimated; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 110. | J/mol*K | N/A | Meot-Ner (Mautner), Hamlet, et al., 1978 | gas phase; Entropy change calculated or estimated; M |
Free energy of reaction
ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
26. | 300. | PHPMS | Meot-Ner (Mautner), Hamlet, et al., 1978 | gas phase; Entropy change calculated or estimated; M |
C8H9- + =
By formula: C8H9- + H+ = C8H10
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1594. ± 11. | kJ/mol | G+TS | Caldwell and Bartmess | gas phase; value altered from reference due to change in acidity scale; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1564. ± 10. | kJ/mol | IMRE | Caldwell and Bartmess | gas phase; value altered from reference due to change in acidity scale; B |
By formula: Cl- + C8H10 = (Cl- • C8H10)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrG° | 16.3 | kJ/mol | TDEq | French, Ikuta, et al., 1982 | gas phase; B |
Free energy of reaction
ΔrG° (kJ/mol) | T (K) | Method | Reference | Comment |
---|---|---|---|---|
18. | 300. | PHPMS | French, Ikuta, et al., 1982 | gas phase; M |
Gas phase ion energetics data
Go To: Top, Reaction thermochemistry data, 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
L - Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
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 C8H10+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 8.55 ± 0.02 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 812.1 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 786.2 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Proton affinity at 298K
Proton affinity (kJ/mol) | Reference | Comment |
---|---|---|
816.7 | Aue, Guidoni, et al., 2000 | Experimental literature data re-evaluated by the authors using ab initio protonation entropies; MM |
809.1 ± 1.2 | Fernandez, Jennings, et al., 1989 | T = 370 - 750K; Reference Sprot(CH3)2O = 16.5 J/mol K in Hunter and Lias, 1998 needs to be re-evaluated; MM |
Gas basicity at 298K
Gas basicity (review) (kJ/mol) | Reference | Comment |
---|---|---|
787.8 | Aue, Guidoni, et al., 2000 | Experimental literature data re-evaluated by the authors using ab initio protonation entropies; MM |
782.4 ± 1.8 | Fernandez, Jennings, et al., 1989 | T = 370 - 750K; Reference Sprot(CH3)2O = 16.5 J/mol K in Hunter and Lias, 1998 needs to be re-evaluated; MM |
Protonation entropy at 298K
Protonation entropy (J/mol*K) | Reference | Comment |
---|---|---|
19.2 | Fernandez, Jennings, et al., 1989 | T = 370 - 750K; Reference Sprot(CH3)2O = 16.5 J/mol K in Hunter and Lias, 1998 needs to be re-evaluated; MM |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
8.56 | PE | Howell, Goncalves, et al., 1984 | LBLHLM |
8.57 ± 0.01 | EQ | Lias and Ausloos, 1978 | LLK |
8.90 ± 0.05 | EI | Loudon and Mazengo, 1974 | LLK |
8.50 ± 0.02 | PE | Maier and Turner, 1973 | LLK |
8.55 ± 0.05 | PI | Akopyan and Vilesov, 1966 | RDSH |
8.56 | PI | Bralsford, Harris, et al., 1960 | RDSH |
8.56 ± 0.01 | PI | Watanabe, 1957 | RDSH |
8.56 | PE | Howell, Goncalves, et al., 1984 | Vertical value; LBLHLM |
8.82 | PE | Kimura, Katsumata, et al., 1981 | Vertical value; LLK |
8.55 | PE | Koenig, Tuttle, et al., 1974 | Vertical value; LLK |
8.71 ± 0.015 | PE | Kobayashi and Nagakura, 1972 | Vertical value; LLK |
8.75 ± 0.03 | PE | Klessinger, 1972 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C7H7+ | 11.8 ± 0.2 | CH3 | EI | Loudon and Mazengo, 1974 | LLK |
C7H7+ | 11.4 ± 0.1 | CH3 | EI | Nounou, 1966 | RDSH |
C7H7+ | 11.3 ± 0.1 | CH3 | PI | Akopyan and Vilesov, 1966 | RDSH |
C8H9+ | 12.3 ± 0.2 | H | EI | Loudon and Mazengo, 1974 | LLK |
C8H9+ | 11.7 ± 0.1 | H | PI | Akopyan and Vilesov, 1966 | RDSH |
C8H9+ | 11.8 ± 0.1 | H | EI | Tait, Shannon, et al., 1962 | RDSH |
De-protonation reactions
C8H9- + =
By formula: C8H9- + H+ = C8H10
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 1594. ± 11. | kJ/mol | G+TS | Caldwell and Bartmess | gas phase; value altered from reference due to change in acidity scale; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 1564. ± 10. | kJ/mol | IMRE | Caldwell and Bartmess | gas phase; value altered from reference due to change in acidity scale; B |
References
Go To: Top, 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.
Wojtyniak and Stone, 1986
Wojtyniak, A.C.M.; Stone, A.J.,
A High-Pressure Mass Spectrometric Study of the Bonding of Trimethylsilylium to Oxygen and Aromatic Bases,
Can. J. Chem., 1986, 74, 59. [all data]
Meot-Ner (Mautner), Hamlet, et al., 1978
Meot-Ner (Mautner), M.; Hamlet, P.; Hunter, E.P.; Field, F.H.,
Bonding Energies in Association Ions of Aromatic Molecules. Correlations with Ionization Energies,
J. Am. Chem. Soc., 1978, 100, 17, 5466, https://doi.org/10.1021/ja00485a034
. [all data]
Caldwell and Bartmess
Caldwell, G.; Bartmess, J.E.,
, Unpublished results. [all data]
French, Ikuta, et al., 1982
French, M.A.; Ikuta, S.; Kebarle, P.,
Hydrogen bonding of O-H and C-H hydrogen donors to Cl-. Results from mass spectrometric measurement of the ion-molecule equilibria RH + Cl- = RHCl-,
Can. J. Chem., 1982, 60, 1907. [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]
Aue, Guidoni, et al., 2000
Aue, D.H.; Guidoni, M.; Betowski, L.D.,
Ab initio calculated gas-phase basicities of polynuclear aromatic hydrocarbons,
Int. J. Mass Spectrom., 2000, 201, 283. [all data]
Fernandez, Jennings, et al., 1989
Fernandez, T.; Jennings, K.R.; Mason, R.S.,
Gas-phase proton transfer reactions in xylene-dimethyl ether mixtures,
J. Chem. Soc. Faraday Trans. 2, 1989, 85, 1813. [all data]
Howell, Goncalves, et al., 1984
Howell, J.O.; Goncalves, J.M.; Amatore, C.; Klasinc, L.; Wightman, R.M.; Kochi, J.K.,
Electron transfer from aromatic hydrocarbons and their π-complexes with metals. Comparison of the standard oxidation potentials and vertical ionization potentials,
J. Am. Chem. Soc., 1984, 106, 3968. [all data]
Lias and Ausloos, 1978
Lias, S.G.; Ausloos, P.J.,
eIonization energies of organic compounds by equilibrium measurements,
J. Am. Chem. Soc., 1978, 100, 6027. [all data]
Loudon and Mazengo, 1974
Loudon, A.G.; Mazengo, R.Z.,
Steric strain and electron-impact. The behaviour of some n, n'-dimethyl- 1,1-binaphthyls, some n, n'-dimethylbiphenyls and model compounds,
Org. Mass Spectrom., 1974, 8, 179. [all data]
Maier and Turner, 1973
Maier, J.P.; Turner, D.W.,
Steric inhibition of resonance studied by molecular photoelectron spectroscopy. Part 2. Phenylethylenes,
J. Chem. Soc. Faraday Trans. 2, 1973, 69, 196. [all data]
Akopyan and Vilesov, 1966
Akopyan, M.E.; Vilesov, F.I.,
A mass-spectrometric study of the photo-ionisation of benzene derivatives at wavelengths up to 885 A,
Zh. Fiz. Khim., 1966, 40, 125, In original 63. [all data]
Bralsford, Harris, et al., 1960
Bralsford, R.; Harris, P.V.; Price, W.C.,
The effect of fluorine on the electronic spectra and ionization potentials of molecules,
Proc. Roy. Soc. (London), 1960, A258, 459. [all data]
Watanabe, 1957
Watanabe, K.,
Ionization potentials of some molecules,
J. Chem. Phys., 1957, 26, 542. [all data]
Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S.,
Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules
in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]
Koenig, Tuttle, et al., 1974
Koenig, T.; Tuttle, M.; Wielesek, R.A.,
The He(I) photoelectron spectra of xylenes and metacyclophanes. A reassignment of the lowest ionic state of [2.2] metacyclophane,
Tetrahedron Lett., 1974, 2537. [all data]
Kobayashi and Nagakura, 1972
Kobayashi, T.; Nagakura, S.,
Photoelectron spectra of nitro-compounds,
Chem. Lett., 1972, 903. [all data]
Klessinger, 1972
Klessinger, M.,
Ionization potentials of substituted benzenes,
Angew. Chem. Int. Ed. Engl., 1972, 11, 525. [all data]
Nounou, 1966
Nounou, P.,
Etude des composes aromatiques par spectrometrie de masse. I. Mesure des potentials d'ionisation et d'apparition par la methode du potential retardateur et interpretation des courbes d'ionisation differentielle,
J. Chim. Phys., 1966, 63, 994. [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]
Notes
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy T Temperature ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔrS° Entropy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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