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:
  • Gas phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • Gas Chromatography
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change data
• Options:
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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

Constant pressure heat capacity of gas

Reaction 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
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias

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: C₁₂H₁₈ = C₁₂H₁₈

=

By formula: C₁₂H₁₈ = C₁₂H₁₈

C₆H₇N⁺ +  = (C₆H₇N⁺ • )

By formula: C₆H₇N⁺ + C₁₂H₁₈ = (C₆H₇N⁺ • C₁₂H₁₈)

Bond type: Charge transfer bond (positive ion)

=

By formula: C₁₂H₁₈ = C₁₂H₁₈

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
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

Ion clustering 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 by: Michael M. Meot-Ner (Mautner) and Sharon G. Lias

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.

Clustering reactions

C₆H₇N⁺ +  = (C₆H₇N⁺ • )

By formula: C₆H₇N⁺ + C₁₂H₁₈ = (C₆H₇N⁺ • C₁₂H₁₈)

Bond type: Charge transfer bond (positive ion)

IR Spectrum

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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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Gas Phase Spectrum

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Notice: Concentration information is not available for this spectrum and, therefore, molar absorptivity values cannot be derived.

Additional Data

Mass spectrum (electron ionization)

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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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

UV/Visible spectrum

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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 by: Victor Talrose, Eugeny B. Stern, Antonina A. Goncharova, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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Additional Data

Gas Chromatography

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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 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, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, 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]

Adam and Chang, 1969
Adam, W.; Chang, J.C., Kinetics and thermochemistry of valence isomerization by differential scanning calorimetry: the case of hexamethylprismane and hexamethyldewarbenzene, Int. J. Chem. Kinet., 1969, 1, 487-492. [all data]

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]

Oth, 1969
Oth, J.F.M., The kinetics and thermochemistry of the thermal rearrangement of hexamethyl(Dewar benzene) and of hexamethylprismane, Angew. Chem. Int. Ed. Engl., 1969, 7, 646. [all data]

Meot-Ner (Mautner) and El-Shall, 1986
Meot-Ner (Mautner), M.; El-Shall, M.S., Ionic Charge Transfer Complexes. 1. Cationic Complexes with Delocalized and Partially Localized pi Systems, J. Am. Chem. Soc., 1986, 108, 15, 4386, https://doi.org/10.1021/ja00275a026 . [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]

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, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, Ion clustering data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, References

• Symbols used in this document:
  

  Cp,gas	Constant pressure heat capacity of gas
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔrS°	Entropy of reaction at standard conditions

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