p-Xylene

• Formula: C₈H₁₀
• Molecular weight: 106.1650
• IUPAC Standard InChI: InChI=1S/C8H10/c1-7-3-5-8(2)6-4-7/h3-6H,1-2H3 Copy

  
• IUPAC Standard InChIKey: URLKBWYHVLBVBO-UHFFFAOYSA-N Copy
• CAS Registry Number: 106-42-3
• 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:
  • 1,4-Di(methyl-d3)benzene-d4
• Other names: Benzene, 1,4-dimethyl-; p-Dimethylbenzene; p-Xylol; 1,4-Dimethylbenzene; 1,4-Xylene; p-Methyltoluene; para-Xylene; Chromar; Scintillar; 4-Methyltoluene; NSC 72419; UN 1307; 1,4-dimethyl-benzene ( p-xylene)
• 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
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Phase change data
  • Henry's Law data
  • Ion clustering data
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • NIST Polycyclic Aromatic Hydrocarbon Structure Index
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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

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:
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
B - John E. Bartmess
RCD - Robert C. Dunbar

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

C₃H₉Si⁺ +  = (C₃H₉Si⁺ • )

By formula: C₃H₉Si⁺ + C₈H₁₀ = (C₃H₉Si⁺ • C₈H₁₀)

Free energy of reaction

C₈H₉^- +  =

By formula: C₈H₉^- + H⁺ = C₈H₁₀

C₆H₇N⁺ +  = (C₆H₇N⁺ • )

By formula: C₆H₇N⁺ + C₈H₁₀ = (C₆H₇N⁺ • C₈H₁₀)

Bond type: Charge transfer bond (positive ion)

Free energy of reaction

C₈H₁₀⁺ +  = (C₈H₁₀⁺ • )

By formula: C₈H₁₀⁺ + C₈H₁₀ = (C₈H₁₀⁺ • C₈H₁₀)

Bond type: Charge transfer bond (positive ion)

C₉H₁₂⁺ +  = (C₉H₁₂⁺ • )

By formula: C₉H₁₂⁺ + C₈H₁₀ = (C₉H₁₂⁺ • C₈H₁₀)

Bond type: Charge transfer bond (positive ion)

 +  = ( • )

By formula: Cl^- + C₈H₁₀ = (Cl^- • C₈H₁₀)

Free energy of reaction

( • ) +  = ( • 2)

By formula: (Cr⁺ • C₈H₁₀) + C₈H₁₀ = (Cr⁺ • 2C₈H₁₀)

 +  = ( • )

By formula: Cr⁺ + C₈H₁₀ = (Cr⁺ • C₈H₁₀)

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:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
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 C₈H₁₀⁺ (ion structure unspecified)

Electron affinity determinations

Proton affinity at 298K

Gas basicity at 298K

Protonation entropy at 298K

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₈H₉^- +  =

By formula: C₈H₉^- + H⁺ = C₈H₁₀

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

• LIQUID; PERKIN-ELMER; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution
• SOLUTION (10% IN CCl4 FOR 3800-1300, 10% IN CS2 FOR 1300-650, AND 10% CCl4 FOR 650-240 CM^-1) VERSUS SOLVENT; PERKIN-ELMER 521 (GRATING); DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution
• VAPOR (0.5 MICROLITER AT 195 C); NICOLET FTIR; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 CM^-1 cm^-1 resolution
• VAPOR (5 mmHg, N2 ADDED, TOTAL PRESSURE 600 mmHg); PERKIN-ELMER 180; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 1 CM^-1 cm^-1 resolution

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

• gas

Data compiled by: Pamela M. Chu, Franklin R. Guenther, George C. Rhoderick, and Walter J. Lafferty

• gas; IFS66V (Bruker); 3-Term B-H Apodization
  0.1250, 0.2410, 0.4820, 0.9640, 1.9290 cm^-1 resolution
• gas; IFS66V (Bruker); Boxcar Apodization
  0.1250, 0.2410, 0.4820, 0.9640, 1.9290 cm^-1 resolution
• gas; IFS66V (Bruker); Happ Genzel Apodization
  0.1250, 0.2410, 0.4820, 0.9640, 1.9290 cm^-1 resolution
• gas; IFS66V (Bruker); NB Strong Apodization
  0.1250, 0.2410, 0.4820, 0.9640, 1.9290 cm^-1 resolution
• gas; IFS66V (Bruker); Triangular Apodization
  0.1250, 0.2410, 0.4820, 0.9640, 1.9290 cm^-1 resolution

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

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), Notes

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

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]

Chao J., 1986
Chao J., Thermodynamic properties of key organic oxygen compounds in the carbon range C1 to C4. Part 2. Ideal gas properties, J. Phys. Chem. Ref. Data, 1986, 15, 1369-1436. [all data]

Pitzer K.S., 1943
Pitzer K.S., The thermodynamics and molecular structure of benzene and its methyl derivatives, J. Am. Chem. Soc., 1943, 65, 803-829. [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]

Draeger J.A., 1981
Draeger J.A., Ideal gas thermodynamic properties of 1,4-dimethylbenzene, J. Chem. Phys., 1981, 74, 4748-4749. [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]

Hossenlopp I.A., 1981
Hossenlopp I.A., Vapor heat capacities and enthalpies of vaporization of four aromatic and/or cycloalkane hydrocarbons, J. Chem. Thermodyn., 1981, 13, 423-428. [all data]

Wojtyniak and Stone, 1986
Wojtyniak, A.C.M.; Stone, A.J., A High-Pressure Mass Spectrometric Study of the Bonding of Trimethylsilylium to Oxygen and Aromatic Bases, Can. J. Chem., 1986, 74, 59. [all data]

Bartmess, Scott, et al., 1979
Bartmess, J.E.; Scott, J.A.; McIver, R.T., Jr., The gas phase acidity scale from methanol to phenol, J. Am. Chem. Soc., 1979, 101, 6047. [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]

Meot-Ner (Mautner), Hamlet, et al., 1978
Meot-Ner (Mautner), M.; Hamlet, P.; Hunter, E.P.; Field, F.H., Bonding Energies in Association Ions of Aromatic Molecules. Correlations with Ionization Energies, J. Am. Chem. Soc., 1978, 100, 17, 5466, https://doi.org/10.1021/ja00485a034 . [all data]

French, Ikuta, et al., 1982
French, M.A.; Ikuta, S.; Kebarle, P., Hydrogen bonding of O-H and C-H hydrogen donors to Cl^-. Results from mass spectrometric measurement of the ion-molecule equilibria RH + Cl^- = RHCl^-, Can. J. Chem., 1982, 60, 1907. [all data]

Lin and Dunbar, 1997
Lin, C.-Y.; Dunbar, R.C., Radiative Association Kinetics and Binding Energies of Chromium Ions with Benzene and Benzene Derivatives, Organometallics, 1997, 16, 12, 2691, https://doi.org/10.1021/om960949n . [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]

Hammer, Diri, et al., 2003
Hammer, N.I.; Diri, K.; Jordan, K.D.; Desfrancois, C.; Compton, R.N., Dipole-bound anions of carbonyl, nitrile, and sulfoxide containing molecules, J. Chem. Phys., 2003, 119, 7, 3650-3660, https://doi.org/10.1063/1.1590959 . [all data]

Aue, Guidoni, et al., 2000
Aue, D.H.; Guidoni, M.; Betowski, L.D., Ab initio calculated gas-phase basicities of polynuclear aromatic hydrocarbons, Int. J. Mass Spectrom., 2000, 201, 283. [all data]

Fernandez, Jennings, et al., 1989
Fernandez, T.; Jennings, K.R.; Mason, R.S., Gas-phase proton transfer reactions in xylene-dimethyl ether mixtures, J. Chem. Soc. Faraday Trans. 2, 1989, 85, 1813. [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]

Bock, Kaim, et al., 1978
Bock, H.; Kaim, W.; Rohwer, H.E., Die hyperkonjugative Stabilisierung von p-Xylol-Radikalkationen durch (H₃C)₃Si-Substituenten, Chem. Ber., 1978, 111, 3573. [all data]

Loudon and Mazengo, 1974
Loudon, A.G.; Mazengo, R.Z., Steric strain and electron-impact. The behaviour of some n, n'-dimethyl- 1,1-binaphthyls, some n, n'-dimethylbiphenyls and model compounds, Org. Mass Spectrom., 1974, 8, 179. [all data]

Maier and Turner, 1973
Maier, J.P.; Turner, D.W., Steric inhibition of resonance studied by molecular photoelectron spectroscopy. Part 2. Phenylethylenes, J. Chem. Soc. Faraday Trans. 2, 1973, 69, 196. [all data]

Kinoshita, 1962
Kinoshita, M., The absorption spectra of the molecular complexes of aromatic compounds with p-bromanil, Bull. Chem. Soc. Japan, 1962, 35, 1609. [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]

Vilesov and Terenin, 1957
Vilesov, F.I.; Terenin, A.N., The photoionization of the vapors of certain organic compounds, Dokl. Akad. Nauk SSSR, 1957, 115, 744, In original 539. [all data]

Watanabe, 1954
Watanabe, K., Photoionization and total absorption cross section of gases. I. Ionization potentials of several molecules. Cross sections of NH₃ and NO, J. Chem. Phys., 1954, 22, 1564. [all data]

Hammond, Price, et al., 1950
Hammond, V.J.; Price, W.C.; Teegan, J.P.; Walsh, A.D., The absorption spectra of some substituted benzenes and naphthalenes in the vacuum ultra-violet, Faraday Discuss. Chem. Soc., 1950, 9, 53. [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]

Koenig, Tuttle, et al., 1974
Koenig, T.; Tuttle, M.; Wielesek, R.A., The He(I) photoelectron spectra of xylenes and metacyclophanes. A reassignment of the lowest ionic state of [2.2] metacyclophane, Tetrahedron Lett., 1974, 2537. [all data]

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

Tajima and Tsuchiya, 1973
Tajima, S.; Tsuchiya, T., Energetics consideration of C₅H₅⁺ ions produced from various precursors by electron impact, Bull. Chem. Soc. Jpn., 1973, 46, 3291. [all data]

McLafferty and Winkler, 1974
McLafferty, F.W.; Winkler, J., Gaseous tropylium, benzyl, tolyl, and norbornadienyl cations, J. Am. Chem. Soc., 1974, 96, 5182. [all data]

Akopyan and Vilesov, 1968
Akopyan, M.E.; Vilesov, F.I., Mass-spectrometric investigation of the photo-ionization of benzene and its methyl derivatives, Khim. Vysokikh Energ., 1968, 2, 107, In original 89. [all data]

Nounou, 1966
Nounou, P., Etude des composes aromatiques par spectrometrie de masse. I. Mesure des potentials d'ionisation et d'apparition par la methode du potential retardateur et interpretation des courbes d'ionisation differentielle, J. Chim. Phys., 1966, 63, 994. [all data]

Tait, Shannon, et al., 1962
Tait, J.M.S.; Shannon, T.W.; Harrison, A.G., The structure of substituted C₇ ions from benzyl derivatives at the appearance potential threshold, J. Am. Chem. Soc., 1962, 84, 4. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  AE	Appearance energy
  Cp,gas	Constant pressure heat capacity of gas
  EA	Electron affinity
  IE (evaluated)	Recommended ionization energy
  T	Temperature
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔrG°	Free energy of reaction 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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