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Benzene, hexamethyl-

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Condensed 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Deltafliquid-33.94kcal/molCcbOth, 1968ALS
Quantity Value Units Method Reference Comment
Deltacliquid-1705.2 ± 1.7kcal/molCcbBanse and Parks, 1933Reanalyzed by Cox and Pilcher, 1970, Original value = -1703.88 kcal/mol; Corresponding «DELTA»fliquid = -38.25 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity Value Units Method Reference Comment
Deltafsolid-38.81 ± 0.60kcal/molCcbColomina, Jimenez, et al., 1989see Boned, Colomina, et al., 1964; ALS
Deltafsolid-39.03 ± 0.73kcal/molCcbParks, West, et al., 1946Reanalyzed by Cox and Pilcher, 1970, Original value = -39.19 ± 0.02 kcal/mol; ALS
Quantity Value Units Method Reference Comment
Deltacsolid-1704.6 ± 0.45kcal/molCcbColomina, Jimenez, et al., 1989see Boned, Colomina, et al., 1964; Corresponding «DELTA»fsolid = -38.81 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Deltacsolid-1700.1 ± 1.3kcal/molCcbHoldiness, 1984Hf NR; Corresponding «DELTA»fsolid = -43.3 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Deltacsolid-1704.42 ± 0.72kcal/molCcbParks, West, et al., 1946Reanalyzed by Cox and Pilcher, 1970, Original value = -1704.29 ± 0.68 kcal/mol; Corresponding «DELTA»fsolid = -39.03 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity Value Units Method Reference Comment
solid,1 bar72.373cal/mol*KN/AAtake, Gyoten, et al., 1982DH
solid,1 bar73.210cal/mol*KN/AFrankosky and Aston, 1965crystaline, I phase; DH
solid,1 bar74.00cal/mol*KN/AHuffman, Parks, et al., 1930crystaline, I phase; Extrapolation below 90 K, 82.38 J/mol*K.; DH

Constant pressure heat capacity of liquid

Cp,liquid (cal/mol*K) Temperature (K) Reference Comment
88.60455.Kurbatov, 1947T = 183 to 256°C, mean Cp, two temperatures.; DH

Constant pressure heat capacity of solid

Cp,solid (cal/mol*K) Temperature (K) Reference Comment
58.17298.15Colomina, Jimenez, et al., 1989DH
60.256300.Atake, Gyoten, et al., 1982T = 3 to 300 K.; DH
58.709298.15Frankosky and Aston, 1965crystaline, I phase; T = 13 to 340 K.; DH
61.21293.81Momotani, Suga, et al., 1956T = 273 to 443 K. Unsmoothed experimental datum.; DH
61.78303.Spaght, Thomas, et al., 1932crystaline, II phase; T = 30 to 200°C.; DH
60.90294.6Huffman, Parks, et al., 1930crystaline, I phase; T = 85 to 294 K. Value is unsmoothed experimental datum.; DH

References

Go To: Top, Condensed phase thermochemistry data, Notes

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

Oth, 1968
Oth, J.F.M., The kinetics and thermochemistry of the thermal rearrangement of hexamethylbicyclo[2.2.0]hexa-2,5-diene (hexamethyldewarbenzene) and of hexamethyltetracyclo[2.2.0,0(2,6).0(3,5)]hexane (hexamethylprismane), Chem. Ber., 1968, 47, 1185-1195. [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]

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]

Holdiness, 1984
Holdiness, M.R., Resonance energy of hexaethylbenzene and hexamethylbenzene, Thermochim. Acta, 1984, 78, 435-436. [all data]

Atake, Gyoten, et al., 1982
Atake, T.; Gyoten, H.; Chihara, H., A concealed anomaly at 117.5 K in the heat capacity of hexamethylbenzene, J. Chem. Phys., 1982, 76(11), 5535-5540. [all data]

Frankosky and Aston, 1965
Frankosky, M.; Aston, J.G., The heat capacity and entropy of hexamethylbenzene from 13 to 340 K. An estimate of the internal rotation barrier, J. Phys. Chem., 1965, 69, 3126-3132. [all data]

Huffman, Parks, et al., 1930
Huffman, H.M.; Parks, G.S.; Daniels, A.C., Thermal data on organic compounds. VII. The heat capacities, entropies and free energies of twelve aromatic hydrocarbons, J. Am. Chem. Soc., 1930, 52, 1547-1558. [all data]

Kurbatov, 1947
Kurbatov, V.Ya., Specific heat of liquids. I. Specific heat of benzenoid hydrocarbons, Zhur. Obshch. Khim., 1947, 17, 1999-2003. [all data]

Momotani, Suga, et al., 1956
Momotani, M.; Suga, H.; Seki, S.; Nitta, I., Phase transitions in crystals composed of organic molecules with methyl groups at the molecular periperies, Proceed. National Academy of Sci. (India), XXV(Section A, part, 1956, II), 74-82. [all data]

Spaght, Thomas, et al., 1932
Spaght, M.E.; Thomas, S.B.; Parks, G.S., Some heat capacity data on organic compounds obtained with a radiation calorimeter, J. Phys. Chem., 1932, 36, 882-888. [all data]


Notes

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