Benzene, 1,2,3-trimethyl-

• Formula: C₉H₁₂
• Molecular weight: 120.1916
• IUPAC Standard InChI: InChI=1S/C9H12/c1-7-5-4-6-8(2)9(7)3/h4-6H,1-3H3 Copy

  
• IUPAC Standard InChIKey: FYGHSUNMUKGBRK-UHFFFAOYSA-N Copy
• CAS Registry Number: 526-73-8
• 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: Hemimellitene; 1,2,3-Trimethylbenzene; Hemellitol; 1,2,3-TrimethyIbenzene; 1,2,3-trimethylbenzene (hemimellitene)
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• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Henry's Law data
  • Gas phase ion energetics data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • References
  • Notes
• Other data available:
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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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
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Constant pressure heat capacity of gas

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

Constant pressure heat capacity of liquid

Phase change 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:
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

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
    P = vapor pressure (bar)
    T = temperature (K)

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Enthalpy of fusion

Entropy of fusion

Enthalpy of phase transition

Entropy of phase transition

Henry's Law 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: Rolf Sander

Henry's Law constant (water solution)

k_H(T) = k°_H exp(d(ln(k_H))/d(1/T) ((1/T) - 1/(298.15 K)))
k°_H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(k_H))/d(1/T) = Temperature dependence constant (K)

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:
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

View reactions leading to C₉H₁₂⁺ (ion structure unspecified)

Ionization energy determinations

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

• LIQUID (NEAT); PERKIN-ELMER 521 (GRATING); DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution

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

• gas

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

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Henry's Law data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Notes

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

Johnson, Prosen, et al., 1945
Johnson, W.H.; Prosen, E.J.; Rossini, F.D., Heats of combustion and isomerization of the eight C₉H₁₂ alkylbenzenes, J. Res. NBS, 1945, 35, 141-146. [all data]

Prosen, Johnson, et al., 1946
Prosen, E.J.; Johnson, W.H.; Rossini, F.D., Heats of combustion and formation at 25°C of the alkylbenzenes through C₁₀H₁₄, and of the higher normal monoalkylbenzenes, J. Res. NBS, 1946, 36, 455-461. [all data]

Taylor R.D., 1955
Taylor R.D., Entropy, heat capacity, and heats of transition of 1,2,3-trimethylbenzene, J. Chem. Phys., 1955, 23, 1225-1231. [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]

Taylor W.J., 1946
Taylor W.J., Heats, equilibrium constants, and free energies of formation of the alkylbenzenes, J. Res. Nat. Bur. Stand., 1946, 37, 95-122. [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]

Thermodynamics Research Center, 1997
Thermodynamics Research Center, Selected Values of Properties of Chemical Compounds., Thermodynamics Research Center, Texas A&M University, College Station, Texas, 1997. [all data]

Taylor, Johnson, et al., 1955
Taylor, R.D.; Johnson, B.H.; Kilpatrick, J.E., Entropy, heat capacity, and heats of transition of 1,2,3-trimethylbenzene, J. Chem. Phys., 1955, 23, 1225-1231. [all data]

Taylor, Johnson, et al., 1955, 2
Taylor, R.D.; Johnson, B.H.; Kilpatrick, J.E., Entropy, Heat Capacity and Heats of Trans. of 1,2,3-Trimethylbenzene, J. Chem. Phys., 1955, 23, 1225. [all data]

Kilpatrick, 1953
Kilpatrick, J.E., Unpublished, 1953. [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]

Kay and Pak, 1980
Kay, W.B.; Pak, S.C., Determination of the critical constants of high-boiling hydrocarbons. Experiments with gallium as a containing fluid, J. Chem. Thermodyn., 1980, 12, 673. [all data]

Ambrose, Broderick, et al., 1967
Ambrose, D.; Broderick, B.E.; Townsend, R., The Vapour Pressures above the Normal Boiling Point and the Critical Pressures of Some Aromatic Hydrocarbons, J. Chem. Soc. , 1967, 1967, 1967, 633-41. [all data]

Ambrose, Cox, et al., 1960
Ambrose, D.; Cox, J.D.; Townsend, R., The critical temperatures of forty organic compounds, Trans. Faraday Soc., 1960, 56, 1452. [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]

Forziati, Norris, et al., 1949
Forziati, Alphonse F.; Norris, William R.; Rossini, Frederick D., Vapor pressures and boiling points of sixty API-NBS hydrocarbons, J. RES. NATL. BUR. STAN., 1949, 43, 6, 555-17, https://doi.org/10.6028/jres.043.050 . [all data]

Hopke and Sears, 1948
Hopke, E.R.; Sears, G.W., Vapor Pressures of Trimethylbenzenes in the Low Pressure Region ^1,2, J. Am. Chem. Soc., 1948, 70, 11, 3801-3803, https://doi.org/10.1021/ja01191a077 . [all data]

Forziati, Norris, et al., 1949, 2
Forziati, A.F.; Norris, W.R.; Rossini, F.D., Vapor Pressures and Boiling Points of Sixty API-NBS Hydrocarbons, J. Res. Natl. Bur. Stand. (U.S.), 1949, 43, 6, 555-563, https://doi.org/10.6028/jres.043.050 . [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]

Lias and Ausloos, 1978
Lias, S.G.; Ausloos, P.J., eIonization energies of organic compounds by equilibrium measurements, J. Am. Chem. Soc., 1978, 100, 6027. [all data]

Price, Bralsford, et al., 1959
Price, W.C.; Bralsford, R.; Harris, P.V.; Ridley, R.G., Ultra-violet spectra and ionization potentials of hydrocarbon molecules, Spectrochim. Acta, 1959, 14, 45. [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]

Klessinger, 1972
Klessinger, M., Ionization potentials of substituted benzenes, Angew. Chem. Int. Ed. Engl., 1972, 11, 525. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Henry's Law data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, References

• Symbols used in this document:
  

  Cp,gas	Constant pressure heat capacity of gas
  Cp,liquid	Constant pressure heat capacity of liquid
  IE (evaluated)	Recommended ionization energy
  Pc	Critical pressure
  S°gas	Entropy of gas at standard conditions
  S°liquid	Entropy of liquid at standard conditions
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  d(ln(kH))/d(1/T)	Temperature dependence parameter for Henry's Law constant
  k°H	Henry's Law constant at 298.15K
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy of phase transition
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  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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