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-
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Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, Gas phase ion energetics 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 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. |
Condensed phase thermochemistry data
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics 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 as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔcH°liquid | -6475.6 ± 6.3 | kJ/mol | Ccb | Banse and Parks, 1933 | Reanalyzed by Cox and Pilcher, 1970, Original value = -6470.64 kJ/mol; Corresponding ΔfHºliquid = -139.7 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔfH°solid | -144.6 ± 2.2 | kJ/mol | Ccb | Colomina, Jimenez, et al., 1989 | see Boned, Colomina, et al., 1964; ALS |
ΔfH°solid | -135.1 ± 2.6 | kJ/mol | Ccb | Parks, West, et al., 1946 | Reanalyzed by Cox and Pilcher, 1970, Original value = -135.7 ± 0.04 kJ/mol; ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -6470.6 ± 1.6 | kJ/mol | Ccb | Colomina, Jimenez, et al., 1989 | see Boned, Colomina, et al., 1964; Corresponding ΔfHºsolid = -144.7 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°solid | -6480.1 ± 2.6 | kJ/mol | Ccb | Parks, West, et al., 1946 | Reanalyzed by Cox and Pilcher, 1970, Original value = -6479.6 ± 2.6 kJ/mol; Corresponding ΔfHºsolid = -135.1 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°solid,1 bar | 294.1 | J/mol*K | N/A | Huffman, Parks, et al., 1931 | crystaline, I phase; Extrapolation below 90 K, 102.9 J/mol*K.; DH |
Constant pressure heat capacity of solid
Cp,solid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
210.5 | 298.15 | Colomina, Jimenez, et al., 1989 | DH |
270.3 | 298.1 | Eibert, 1944 | crystaline, I phase; T = 25 to 200°C, equations only, in t°C. Cp(c) = 0.3914 + 0.001760t cal/g*K (25 to 40°C); Cp(liq) = 0.432 + 0.000425 t cal/g*K (55 to 200°C).; DH |
267.3 | 303. | Ferry and Thomas, 1933 | T = 303 to 393 K.; DH |
251.0 | 283.8 | Huffman, Parks, et al., 1931 | crystaline, I phase; T = 92 to 304 K. Value is unsmoothed experimental datum.; DH |
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
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 |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, 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]
Banse and Parks, 1933
Banse, H.; Parks, G.S.,
Thermal data on organic compounds. XII. The heats of combustion of nine hydrocarbons,
J. Am. Chem. Soc., 1933, 55, 3223-3227. [all data]
Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G.,
Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]
Huffman, Parks, et al., 1931
Huffman, H.M.; Parks, G.S.; Barmore, M.,
Thermal data on organic compounds. X. Further studies on the heat capacities, entropies and free energies of hydrocarbons,
J. Am. Chem. Soc., 1931, 53, 3876-3888. [all data]
Eibert, 1944
Eibert, J.,
Thesis Washington University (St. Louis), 1944. [all data]
Ferry and Thomas, 1933
Ferry, J.D.; Thomas, S.B.,
Some heat capacity data for durene, pentamethylbenzene, stilbene, and dibenzyl,
J. Phys. Chem., 1933, 37, 253-255. [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]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Cp,solid Constant pressure heat capacity of solid EA Electron affinity S°solid,1 bar Entropy of solid at standard conditions (1 bar) ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°solid Enthalpy of formation of solid at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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