Benzene, pentamethyl-

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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-16.1 ± 0.53kcal/molCcbColomina, Jimenez, et al., 1989see Boned, Colomina, et al., 1964; ALS
Δfgas-13.8kcal/molN/AParks, West, et al., 1946Value computed using ΔfHsolid° value of -135.1±2.6 kj/mol from Parks, West, et al., 1946 and ΔsubH° value of 77.4 kj/mol from Colomina, Jimenez, et al., 1989.; DRB

Constant pressure heat capacity of gas

Cp,gas (cal/mol*K) Temperature (K) Reference Comment
38.79200.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
50.79 ± 0.1298.15


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

Colomina, Jimenez, et al., 1989
Colomina, M.; Jimenez, P.; Roux, M.V.; Turrion, C., Thermochemical properties of 1,2,4,5-tetramethylbenzene, pentamethylbenzene, and hexamethylbenzene, J. Chem. Thermodyn., 1989, 21, 275-281. [all data]

Boned, Colomina, et al., 1964
Boned, M.L.; Colomina, M.; Perez-Ossorio, R.; Turrion, C., Investigaciones termoquimicas sobre los polimetilbencenos superiores, Anal. Fisc. Quim. B, 1964, 60, 459-468. [all data]

Parks, West, et al., 1946
Parks, G.S.; West, T.J.; Naylor, B.F.; Fujii, P.S.; McClaine, L.A., Thermal data on organic compounds. XXIII. Modern combustion data for fourteen hydrocarbons and five polyhydroxy alcohols, J. Am. Chem. Soc., 1946, 68, 2524-2527. [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]

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]


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