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
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
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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 |
|---|---|---|---|---|---|
| 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. |
Condensed phase thermochemistry data
Go To: Top, Gas phase thermochemistry data, Reaction 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 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 | -1547.7 ± 1.5 | kcal/mol | Ccb | Banse and Parks, 1933 | Reanalyzed by Cox and Pilcher, 1970, Original value = -1546.52 kcal/mol; Corresponding ΔfHºliquid = -33.38 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔfH°solid | -34.56 ± 0.53 | kcal/mol | Ccb | Colomina, Jimenez, et al., 1989 | see Boned, Colomina, et al., 1964; ALS |
| ΔfH°solid | -32.29 ± 0.62 | kcal/mol | Ccb | Parks, West, et al., 1946 | Reanalyzed by Cox and Pilcher, 1970, Original value = -32.44 ± 0.01 kcal/mol; ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°solid | -1546.5 ± 0.38 | kcal/mol | Ccb | Colomina, Jimenez, et al., 1989 | see Boned, Colomina, et al., 1964; Corresponding ΔfHºsolid = -34.58 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
| ΔcH°solid | -1548.79 ± 0.61 | kcal/mol | Ccb | Parks, West, et al., 1946 | Reanalyzed by Cox and Pilcher, 1970, Original value = -1548.67 ± 0.62 kcal/mol; Corresponding ΔfHºsolid = -32.29 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| S°solid,1 bar | 70.29 | cal/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 (cal/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 50.31 | 298.15 | Colomina, Jimenez, et al., 1989 | DH |
| 64.60 | 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 |
| 63.89 | 303. | Ferry and Thomas, 1933 | T = 303 to 393 K.; DH |
| 59.99 | 283.8 | Huffman, Parks, et al., 1931 | crystaline, I phase; T = 92 to 304 K. Value is unsmoothed experimental datum.; DH |
Reaction thermochemistry data
Go To: Top, Gas phase thermochemistry data, Condensed 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: 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° | -32.6 ± 0.6 | kcal/mol | Ciso | Childs and Mulholland, 1983 | liquid phase |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry 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]
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]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Cp,solid Constant pressure heat capacity of solid 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 ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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