o-Xylene

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Gas phase thermochemistry data

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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
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Quantity Value Units Method Reference Comment
Δfgas4.54 ± 0.26kcal/molCcbProsen, Gilmont, et al., 1945Hf by Prosen, Johnson, et al., 1946; ALS
Quantity Value Units Method Reference Comment
gas84.50 ± 0.30cal/mol*KN/APitzer K.S., 1943GT

Constant pressure heat capacity of gas

Cp,gas (cal/mol*K) Temperature (K) Reference Comment
22.96200.Draeger, 1985Discrepancies with other statistically calculated values of S(T) and Cp(T) [ Pitzer K.S., 1943, Taylor W.J., 1946, Hastings S.H., 1957, Chao J., 1984] do not exceed 1.5 J/mol*K.; GT
29.37273.15
31.67 ± 0.1298.15
31.84300.
41.01400.
49.24500.
56.19600.
62.02700.
66.92800.
71.08900.
74.621000.
77.651100.
80.261200.
82.501300.
84.441400.
86.111500.

Constant pressure heat capacity of gas

Cp,gas (cal/mol*K) Temperature (K) Reference Comment
40.20 ± 0.40393.Taylor W.J., 1946Please also see Pitzer K.S., 1943.; GT
43.50 ± 0.40428.
46.00 ± 0.50463.

Gas phase ion energetics data

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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:
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)8.56 ± 0.04eVN/AN/AL
Quantity Value Units Method Reference Comment
Proton affinity (review)190.2kcal/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity183.6kcal/molN/AHunter and Lias, 1998HL

Proton affinity at 298K

Proton affinity (kcal/mol) Reference Comment
189.1Aue, Guidoni, et al., 2000Experimental literature data re-evaluated by the authors using ab initio protonation entropies; MM
189.7 ± 0.41Fernandez, Jennings, et al., 1989T = 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) (kcal/mol) Reference Comment
182.9Aue, Guidoni, et al., 2000Experimental literature data re-evaluated by the authors using ab initio protonation entropies; MM
184.5 ± 0.53Fernandez, Jennings, et al., 1989T = 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 (cal/mol*K) Reference Comment
8.82Fernandez, Jennings, et al., 1989T = 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 ± 0.01EQLias and Ausloos, 1978LLK
8.85 ± 0.05EILoudon and Mazengo, 1974LLK
8.45 ± 0.02PEMaier and Turner, 1973LLK
8.70CTSKobayashi, Kobayashi, et al., 1973LLK
8.6 ± 0.1EIGilbert, Leach, et al., 1973LLK
8.61CTSPitt, 1970RDSH
8.555PIBralsford, Harris, et al., 1960RDSH
8.56 ± 0.01PIWatanabe, 1957RDSH
8.56 ± 0.02PIVilesov and Terenin, 1957RDSH
8.58 ± 0.01SHammond, Price, et al., 1950RDSH
8.56PEHowell, Goncalves, et al., 1984Vertical value; LBLHLM
8.57 ± 0.03PEHeilbronner, Hoshi, et al., 1976Vertical value; LLK
8.57PEBrogli, Giovannini, et al., 1973Vertical value; LLK
8.75 ± 0.03PEKlessinger, 1972Vertical value; LLK

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C7H7+11.8 ± 0.2CH3EILoudon and Mazengo, 1974LLK
C7H7+11.10 ± 0.05CH3PIAkopyan and Vilesov, 1968RDSH
C7H7+11.2 ± 0.1CH3EINounou, 1966RDSH
C8H9+12.1 ± 0.2HEILoudon and Mazengo, 1974LLK
C8H9+11.30 ± 0.05HPIAkopyan and Vilesov, 1968RDSH

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Data compiled by: Pamela M. Chu, Franklin R. Guenther, George C. Rhoderick, and Walter J. Lafferty


References

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, IR Spectrum, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Prosen, Gilmont, et al., 1945
Prosen, E.J.; Gilmont, R.; Rossini, F.D., Heats of combustion of benzene, toluene, ethyl-benzene, o-xylene, m-xylene, p-xylene, n-propylbenzene, and styrene, J. Res. NBS, 1945, 34, 65-70. [all data]

Prosen, Johnson, et al., 1946
Prosen, E.J.; Johnson, W.H.; Rossini, F.D., Heats of combustion and formation at 25°C of the alkylbenzenes through C10H14, and of the higher normal monoalkylbenzenes, J. Res. NBS, 1946, 36, 455-461. [all data]

Pitzer K.S., 1943
Pitzer K.S., The thermodynamics and molecular structure of benzene and its methyl derivatives, J. Am. Chem. Soc., 1943, 65, 803-829. [all data]

Draeger, 1985
Draeger, J.A., The methylbenzenes II. Fundamental vibrational shifts, statistical thermodynamic functions, and properties of formation, J. Chem. Thermodyn., 1985, 17, 263-275. [all data]

Taylor W.J., 1946
Taylor W.J., Heats, equilibrium constants, and free energies of formation of the alkylbenzenes, J. Res. Nat. Bur. Stand., 1946, 37, 95-122. [all data]

Hastings S.H., 1957
Hastings S.H., Thermodynamic properties of selected methylbenzenes from 0 to 1000 K, J. Phys. Chem., 1957, 61, 730-735. [all data]

Chao J., 1984
Chao J., Chemical thermodynamic properties of toluene, o-, m- and p-xylenes, Thermochim. Acta, 1984, 72, 323-334. [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]

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]

Kobayashi, Kobayashi, et al., 1973
Kobayashi, H.; Kobayashi, M.; Kaizu, Y., Molecular complexes of arenetricarbonylchromium, Bull. Chem. Soc. Jpn., 1973, 46, 3109. [all data]

Gilbert, Leach, et al., 1973
Gilbert, J.R.; Leach, W.P.; Miller, J.R., Ionisation appearance potential measurements in arene chromium tricarbonyls, J. Organomet. Chem., 1973, 49, 219. [all data]

Pitt, 1970
Pitt, C.G., Hyperconjugation: An alternative to the concept of the pπ-dπ bond in Group IV chemistry, J. Organomet. Chem., 1970, 23, 35. [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]

Vilesov and Terenin, 1957
Vilesov, F.I.; Terenin, A.N., The photoionization of the vapors of certain organic compounds, Dokl. Akad. Nauk SSSR, 1957, 115, 744, In original 539. [all data]

Hammond, Price, et al., 1950
Hammond, V.J.; Price, W.C.; Teegan, J.P.; Walsh, A.D., The absorption spectra of some substituted benzenes and naphthalenes in the vacuum ultra-violet, Faraday Discuss. Chem. Soc., 1950, 9, 53. [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]

Heilbronner, Hoshi, et al., 1976
Heilbronner, E.; Hoshi, T.; von Rosenberg, J.L.; Hafner, K., Alkyl-induced, natural hypsochromic shifts of the 2A←2X and 2B←2X transitions of azulene and naphthalene radical cations, Nouv. J. Chim., 1976, 1, 105. [all data]

Brogli, Giovannini, et al., 1973
Brogli, F.; Giovannini, E.; Heilbronner, E.; Schurter, R., Die photoelektronen spektren der benzocycloalkene, Chem. Ber., 1973, 106, 961. [all data]

Klessinger, 1972
Klessinger, M., Ionization potentials of substituted benzenes, Angew. Chem. Int. Ed. Engl., 1972, 11, 525. [all data]

Akopyan and Vilesov, 1968
Akopyan, M.E.; Vilesov, F.I., Mass-spectrometric investigation of the photo-ionization of benzene and its methyl derivatives, Khim. Vysokikh Energ., 1968, 2, 107, In original 89. [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]


Notes

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