Benzene, 1,2,3,5-tetramethyl-

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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
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Quantity Value Units Method Reference Comment
Δfgas-43.2 ± 1.3kJ/molCcbDraeger, 1985Unpublished measurement of W.D.Good; ALS
Δfgas-44.4 ± 1.2kJ/molN/AGood, 1975Value computed using ΔfHliquid° value of -96.4±1.2 kj/mol from Good, 1975 and ΔvapH° value of 52.0±0.17 kj/mol from missing citation.; DRB
Δfgas-46.5 ± 3.0kJ/molN/AProsen, Johnson, et al., 1946Value computed using ΔfHliquid° value of -98.5±3 kj/mol from Prosen, Johnson, et al., 1946 and ΔvapH° value of 52.0±0.17 kj/mol from missing citation.; DRB

Constant pressure heat capacity of gas

Cp,gas (J/mol*K) Temperature (K) Reference Comment
135.0200.Draeger, 1985There is an appreciable difference between values of S(T) and Cp(T) for tetra-, penta-, and hexamethylbenzene from earlier statistical thermodynamics calculation [ Hastings S.H., 1957] and those obtained by [ Draeger, 1985] (up to 5, 9, and 16 J/mol*K, respectively). Results [ Draeger, 1985] are more reliable and they agree with experimental data for hexamethylbenzene.; GT
168.8273.15
180.7 ± 0.4298.15
181.6300.
229.3400.
273.0500.
310.6600.
342.6700.
369.8800.
393.0900.
413.01000.
430.11100.
444.91200.
457.71300.
468.71400.
478.31500.

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

Data compiled as indicated in comments:
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
B - John E. Bartmess

Quantity Value Units Method Reference Comment
Proton affinity (review)845.6kJ/molN/AHunter and Lias, 1998HL
Quantity Value Units Method Reference Comment
Gas basicity816.5kJ/molN/AHunter and Lias, 1998HL

Electron affinity determinations

EA (eV) Method Reference Comment
<0.108 ± 0.013ECDWojnarovits and Foldiak, 1981EA is an upper limit: Chen and Wentworth, 1989. G3MP2B3 calculations indicate an EA of ca. -0.1 eV, anion unbound.; B

Ionization energy determinations

IE (eV) Method Reference Comment
8.47 ± 0.05EIMeyer and Harrison, 1964RDSH
8.07PEHowell, Goncalves, et al., 1984Vertical value; LBLHLM
8.3 ± 0.03PEKlessinger, 1972Vertical value; LLK

References

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

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]

Good, 1975
Good, W.D., The standard enthalpies of combustion and formation of n-butylbenzene, the dimethylethylbenzenes, and the tetramethylbenzenes in the condensed state, J. Chem. Thermodyn., 1975, 7, 49-59. [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]

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]

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]

Wojnarovits and Foldiak, 1981
Wojnarovits, L.; Foldiak, G., Electron capture detection of aromatic hydrocarbons, J. Chromatogr. Sci., 1981, 206, 511. [all data]

Chen and Wentworth, 1989
Chen, E.C.M.; Wentworth, W.E., Experimental Determination of Electron Affinities of Organic Molecules, Mol. Cryst. Liq. Cryst., 1989, 171, 271. [all data]

Meyer and Harrison, 1964
Meyer, F.; Harrison, A.G., Ionization potentials of methyl-substituted benzenes and cyclopentadienes, Can. J. Chem., 1964, 42, 2256. [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]

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


Notes

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