Benzene, pentamethyl-
- Formula: C11H16
- Molecular weight: 148.2447
- 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
The 3d structure may be viewed using Java or Javascript. - Other names: Pentamethylbenzene; 1,2,3,4,5-Pentamethylbenzene; Benzene, 1,2,3,4,5-pentamethyl-
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Options:
Data at NIST subscription sites:
NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.
Gas phase thermochemistry data
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, 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 | -67.2 ± 2.2 | kJ/mol | Ccb | Colomina, Jimenez, et al., 1989 | see Boned, Colomina, et al., 1964; ALS |
ΔfH°gas | -57.7 | kJ/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 (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
162.3 | 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 |
199.7 | 273.15 | ||
212.5 ± 0.4 | 298.15 | ||
213.4 | 300. | ||
264.4 | 400. | ||
311.4 | 500. | ||
352.3 | 600. | ||
387.4 | 700. | ||
417.5 | 800. | ||
443.4 | 900. | ||
465.6 | 1000. | ||
484.8 | 1100. | ||
501.3 | 1200. | ||
515.6 | 1300. | ||
527.9 | 1400. | ||
538.7 | 1500. |
Reaction thermochemistry data
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
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: C11H16 = C11H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -136. ± 3. | kJ/mol | Ciso | Childs and Mulholland, 1983 | liquid phase |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Mass spectrum (electron ionization), UV/Visible spectrum, 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
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
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess
View reactions leading to C11H16+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Proton affinity (review) | 850.7 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 823.5 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Electron affinity determinations
EA (eV) | Method | Reference | Comment |
---|---|---|---|
<0.182 ± 0.013 | ECD | Wojnarovits and Foldiak, 1981 | EA is an upper limit: Chen and Wentworth, 1989,. G3MP2B3 calculations indicate an EA of ca. -0.5 eV, anion unbound.; B |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
7.92 | PE | Howell, Goncalves, et al., 1984 | LBLHLM |
7.92 | PI | Bralsford, Harris, et al., 1960 | RDSH |
7.9 | CTS | Foster, 1959 | RDSH |
7.92 ± 0.02 | PI | Vilesov and Terenin, 1957 | RDSH |
7.92 | PE | Howell, Goncalves, et al., 1984 | Vertical value; LBLHLM |
Mass spectrum (electron ionization)
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, UV/Visible spectrum, 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
Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.
Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
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 |
UV/Visible spectrum
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, 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.
Spectrum
Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.
Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
View spectrum image in SVG format.
Download spectrum in JCAMP-DX format.
Source | Kusakov, et al., 1963 |
---|---|
Owner | INEP CP RAS, NIST OSRD Collection (C) 2007 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
Origin | INSTITUTE OF ENERGY PROBLEMS OF CHEMICAL PHYSICS, RAS |
Source reference | RAS UV No. 20049 |
Instrument | unknown |
Melting point | 54.5 |
Boiling point | 232 |
References
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, 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]
Childs and Mulholland, 1983
Childs, R.F.; Mulholland, D.L.,
Thermochemical relationships between some bicyclohexenyl and benzenium cations,
J. Am. Chem. Soc., 1983, 105, 96-99. [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]
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]
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]
Foster, 1959
Foster, R.,
Ionization potentials of electron donors,
Nature (London), 1959, 183, 1253. [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]
Kusakov, et al., 1963
Kusakov, M.M., et al.,
Ultraviolet Absorption Spectra of Aromatic Hydrocarbons, 1963, 100. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas EA Electron affinity ΔfH°gas Enthalpy of formation of gas at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.