Benzene, hexamethyl-

• Formula: C₁₂H₁₈
• Molecular weight: 162.2713
• IUPAC Standard InChI: InChI=1S/C12H18/c1-7-8(2)10(4)12(6)11(5)9(7)3/h1-6H3 Copy

  
• IUPAC Standard InChIKey: YUWFEBAXEOLKSG-UHFFFAOYSA-N Copy
• CAS Registry Number: 87-85-4
• 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.
• Isotopologues:
  • Hexamethylbenzene, deuterated
• Other names: Hexamethylbenzene; Mellitene; 1,2,3,4,5,6-Hexamethylbenzene
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Phase change data
  • Gas phase ion energetics data
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
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• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

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Phase change data

Go To: Top, Gas phase ion energetics data, Gas Chromatography, 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of vaporization

Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Temperature of phase transition

Enthalpy of phase transition

Entropy of phase transition

Gas phase ion energetics data

Go To: Top, Phase change data, Gas Chromatography, 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
L - 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
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess

View reactions leading to C₁₂H₁₈⁺ (ion structure unspecified)

Electron affinity determinations

Ionization energy determinations

Gas Chromatography

Go To: Top, Phase change 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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Kovats' RI, non-polar column, isothermal

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Kovats' RI, non-polar column, temperature ramp

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Kovats' RI, polar column, isothermal

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Van Den Dool and Kratz RI, non-polar column, temperature ramp

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Normal alkane RI, non-polar column, temperature ramp

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Normal alkane RI, non-polar column, custom temperature program

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References

Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, Notes

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

Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]

Cooper, Crowne, et al., 1967
Cooper, A.R.; Crowne, C.W.P.; Farrell, P.G., Gas-Liquid Chromatographic Studies of Electron-Donor-Acceptor Systems, Trans. Faraday Soc., 1967, 63, 447. [all data]

Tsonopoulos and Ambrose, 1995
Tsonopoulos, C.; Ambrose, D., Vapor-Liquid Critical Properties of Elements and Compounds. 3. Aromatic Hydrocarbons, J. Chem. Eng. Data, 1995, 40, 547-558. [all data]

Ambrose, Broderick, et al., 1974
Ambrose, D.; Broderick, B.E.; Townsend, R., The Critical Temperatures and Pressures of Thirty Organic Compounds, J. Appl. Chem. Biotechnol., 1974, 24, 359. [all data]

Guye and Mallet, 1902
Guye, P.A.; Mallet, E., Measurement of Critical Constants, Arch. Sci. Phys. Nat., 1902, 13, 274-296. [all data]

Zhao, Unhannanant, et al., 2008
Zhao, Hui; Unhannanant, Patamaporn; Hanshaw, William; Chickos, James S., Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid-Vapor Pressure Isotope Effects, J. Chem. Eng. Data, 2008, 53, 7, 1545-1556, https://doi.org/10.1021/je800091s . [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Ambrose, Lawrenson, et al., 1976
Ambrose, D.; Lawrenson, I.J.; Sprake, C.H.S., The vapour pressure of hexamethylbenzene, The Journal of Chemical Thermodynamics, 1976, 8, 5, 503-504, https://doi.org/10.1016/0021-9614(76)90071-9 . [all data]

Overberger, Steele, et al., 1969
Overberger, John E.; Steele, William A.; Aston, John G., The vapor pressure of hexamethylbenzene the standard entropy of hexamethylbenzene vapor and the barrier to internal rotation, The Journal of Chemical Thermodynamics, 1969, 1, 6, 535-542, https://doi.org/10.1016/0021-9614(69)90014-7 . [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [all data]

Spaght, Thomas, et al., 1931
Spaght, M.E.; Thomas, S.B.; Parks, G.S., Some Heat-Capacity Data on Organic Compounds obtained with a Radiation Calorimeter, J. Phys. Chem., 1931, 36, 3, 882-888, https://doi.org/10.1021/j150333a009 . [all data]

Fujiwara, Inaba, et al., 1992
Fujiwara, T.; Inaba, A.; Atake, T.; Chihara, H., Thermodynamic properties of deuterated hexamethylbenzene and of its solid solutions with the hydrogenated analog. A large isotope effect on the phase transition at the temperature 117 K, J. Chem. Thermodynam., 1992, 24, 863-881. [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]

Petropavlov, Tsygankova, et al., 1988
Petropavlov, N.N.; Tsygankova, I.G.; Teslenko, L.A., Microcalorimetric investigation of polymorphic transitions in organic crystals, Sov. Phys. Crystallogr., 1988, 33(6), 853-855. [all data]

Yoshimoto, Fujiwara, et al., 1985
Yoshimoto, Y.; Fujiwara, T.; Atake, T.; Chihara, H., Solid-solid transition in hexamethylbenzene that depends on thermal history, Chem. Lett., 1985, (9), 1347-1350. [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]

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]

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]

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]

Kuznesof, Stafford, et al., 1967
Kuznesof, P.M.; Stafford, F.E.; Shriver, D.F., Electron impact ionization potentials of methyl-substituted borazines, J. Phys. Chem., 1967, 71, 1939. [all data]

Vilesov, 1961
Vilesov, F.I., Photoionisation of organic vapours in the vacuum ultra-violet, Zh. Fiz. Khim., 1961, 35, 2010, In original 986. [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]

Briegleb and Czekalla, 1959
Briegleb, G.; Czekalla, J., Die Bestimmung von lonisierungsenergien aus den Spektren von Elektronenubergangskomplexen, Z.Elektrochem., 1959, 63, 6. [all data]

Kovac, Mohraz, et al., 1980
Kovac, B.; Mohraz, M.; Heilbronner, E.; Boekelheide, V.; Hopf, H., Photoelectron spectra of the cyclophanes, J. Am. Chem. Soc., 1980, 102, 4314. [all data]

Pérez-Parajón, Santiuste, et al., 2004
Pérez-Parajón, J.M.; Santiuste, J.M.; Takács, J.M., Sensitivity of the methylbenzenes and chlorobenzenes retention index to column temperature, stationary phase polarity, and number and chemical nature of substituents, J. Chromatogr. A, 2004, 1048, 2, 223-232, https://doi.org/10.1016/j.chroma.2004.07.028 . [all data]

Gerasimenko and Nabivach, 1982
Gerasimenko, V.A.; Nabivach, V.M., Relationship between molecular structure and gas chromatographic retention of alkylbenzenes C₈-C_{1 2} on polydimethylsiloxane, Zh. Anal. Khim., 1982, 37, 110-116. [all data]

Gerasimenko, Kirilenko, et al., 1981
Gerasimenko, V.A.; Kirilenko, A.V.; Nabivach, V.M., Capillary gas chromatography of aromatic compounds found in coal tar fractions, J. Chromatogr., 1981, 208, 1, 9-16, https://doi.org/10.1016/S0021-9673(00)87953-4 . [all data]

Engewald and Wennrich, 1976
Engewald, W.; Wennrich, L., Molekülstruktur und Retentionsverhalten. VIII. Zum Retentionsverhalten höherer Alkylbenzole bei der Gas-Verteilungs-Chromatographie, Chromatographia, 1976, 9, 11, 540-547, https://doi.org/10.1007/BF02275960 . [all data]

Hayes and Pitzer, 1982
Hayes, P.C., Jr.; Pitzer, E.W., Characterizing petroleum- and shale-derived jet fuel distillates via temperature-programmed Kováts indices, J. Chromatogr., 1982, 253, 179-198, https://doi.org/10.1016/S0021-9673(01)88376-X . [all data]

White, Hackett, et al., 1992
White, C.M.; Hackett, J.; Anderson, R.R.; Kail, S.; Spock, P.S., Linear temperature programmed retention indices of gasoline range hydrocarbons and chlorinated hydrocarbons on cross-linked polydimethylsiloxane, J. Hi. Res. Chromatogr., 1992, 15, 2, 105-120, https://doi.org/10.1002/jhrc.1240150211 . [all data]

Hayes and Pitzer, 1981
Hayes, P.C., Jr.; Pitzer, E.W., Kovats indices as a tool in characterizing hydrocarbon fuels in temperature programmed glass capillary gas chromatography. Part 1. Qualitative identification, Inhouse rpt. for Air Force Wright Aeronautical Labs., Air Force Wright Aeronautical Labs., Wright-Patterson AFB, Ohio, 1981, 75. [all data]

Supelco, 2012
Supelco, CatalogNo. 24160-U, Petrocol DH Columns. Catalog No. 24160-U, 2012, retrieved from http://www.sigmaaldrich.com/etc/medialib/docs/Supelco/Datasheet/1/w97949.Par.0001.File.tmp/w97949.pdf. [all data]

Waggott and Davies, 1984
Waggott, A.; Davies, I.W., Identification of organic pollutants using linear temperature programmed retention indices (LTPRIs) - Part II, 1984, retrieved from http://dwi.defra.gov.uk/research/completed-research/reports/dwi0383.pdf. [all data]

Notes

Go To: Top, Phase change data, Gas phase ion energetics data, Gas Chromatography, References

• Symbols used in this document:
  

  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttrs	Temperature of phase transition
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy of phase transition
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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