Benzene, pentamethyl-
- Formula: C11H16
- Molecular weight: 148.2447
- IUPAC Standard InChI: InChI=1S/C11H16/c1-7-6-8(2)10(4)11(5)9(7)3/h6H,1-5H3
- IUPAC Standard InChIKey: BEZDDPMMPIDMGJ-UHFFFAOYSA-N
- CAS Registry Number: 700-12-9
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
View 3d structure (requires JavaScript / HTML 5) - Other names: Pentamethylbenzene; 1,2,3,4,5-Pentamethylbenzene; Benzene, 1,2,3,4,5-pentamethyl-
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Gas phase thermochemistry data
Go To: Top, Mass spectrum (electron ionization), 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:
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 |
|---|---|---|---|---|---|
| ΔfH°gas | -16.1 ± 0.53 | kcal/mol | Ccb | Colomina, Jimenez, et al., 1989 | see Boned, Colomina, et al., 1964; ALS |
| ΔfH°gas | -13.8 | kcal/mol | N/A | Parks, West, et al., 1946 | Value 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 |
|---|---|---|---|
| 38.79 | 200. | Draeger, 1985 | There 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 |
| 47.73 | 273.15 | ||
| 50.79 ± 0.1 | 298.15 | ||
| 51.00 | 300. | ||
| 63.19 | 400. | ||
| 74.43 | 500. | ||
| 84.20 | 600. | ||
| 92.59 | 700. | ||
| 99.78 | 800. | ||
| 106.0 | 900. | ||
| 111.3 | 1000. | ||
| 115.9 | 1100. | ||
| 119.8 | 1200. | ||
| 123.2 | 1300. | ||
| 126.2 | 1400. | ||
| 128.8 | 1500. |
Mass spectrum (electron ionization)
Go To: Top, Gas phase 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 compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
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| Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
|---|---|
| Origin | Japan AIST/NIMC Database- Spectrum MS-NW-4461 |
| NIST MS number | 230550 |
References
Go To: Top, Gas phase thermochemistry data, Mass spectrum (electron ionization), Notes
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]
Notes
Go To: Top, Gas phase thermochemistry data, Mass spectrum (electron ionization), References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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