Benzene, 1,2,4-trimethyl-

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

  
• IUPAC Standard InChIKey: GWHJZXXIDMPWGX-UHFFFAOYSA-N Copy
• CAS Registry Number: 95-63-6
• 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: ψ-Cumene; as-Trimethylbenzene; Pseudocumene; Pseudocumol; 1,2,4-Trimethylbenzene; 1,2,5-Trimethylbenzene; 1,3,4-Trimethylbenzene; Psi-cumene; Asymmetrical trimethylbenzene; Benzene, 1,2,5-trimethyl-; NSC 65600; 1,2,4-trimethylbenzene (pseudocumene)
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• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Phase change data
  • Henry's Law data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • Gas Chromatography
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  • 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

Go To: Top, Gas phase thermochemistry 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 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

Gas phase ion energetics 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 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

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, 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]

Putnam W.E., 1957
Putnam W.E., Entropy, heat capacity, and heats of transition of 1,2,4-trimethylbenzene, J. Chem. Phys., 1957, 27, 1075-1080. [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]

Richards and Barry, 1915
Richards, T.W.; Barry, F., The heats of combustion of aromatic hydrocarbons and hexamethylene, J. Am. Chem. Soc., 1915, 37, 993-1020. [all data]

Putnam and Kilpatrick, 1957
Putnam, W.E.; Kilpatrick, J.E., Entropy, heat capacity and heats of transition of 1,2,4-trimethylbenzene, J. Chem. Phys., 1957, 27, 1075-1080. [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]

Wilhelm, Inglese, et al., 1987
Wilhelm, E.; Inglese, A.; Roux, A.H.; Grolier, J.-P.E., Excess enthalpy, excess heat capacity and excess volume of 1,2,4-trimethylbenzene +, and 1-methylnaphthalene + an n-alkane, Fluid Phase Equilibria, 1987, 34, 49-67. [all data]

Andolenko and Grigor'ev, 1979
Andolenko, R.A.; Grigor'ev, B.A., Investigation of isobaric heat capacity of aromatic hydrocarbons at atmospheric pressure, Iaz. Vyssh. Ucheb. Zaved., Neft i Gaz (11), 1979, 78, 90. [all data]

Helfrey, Heiser, et al., 1955
Helfrey, P.F.; Heiser, D.A.; Sage, B.H., Isobaric heat capacities at bubble point, Two trimethylbenzenes and n-heptane, Ind. Eng. Chem., 1955, 44, 2385-2388. [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]

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]

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]

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

Notes

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• 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
  S°gas	Entropy of gas at standard conditions
  S°liquid	Entropy of liquid at standard conditions
  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

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