Pyridine, 4-methyl-

• Formula: C₆H₇N
• Molecular weight: 93.1265
• IUPAC Standard InChI: InChI=1S/C6H7N/c1-6-2-4-7-5-3-6/h2-5H,1H3 Copy

  
• IUPAC Standard InChIKey: FKNQCJSGGFJEIZ-UHFFFAOYSA-N Copy
• CAS Registry Number: 108-89-4
• 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.
• Other names: 4-Picoline; γ-Methylpyridine; γ-Picoline; p-Methylpyridine; p-Picoline; Ba 35846; 4-Methylpyridine; para-Methylpyridine; gamma-Picoline; NSC 18252
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Henry's Law data
  • Gas phase ion energetics data
  • Ion clustering 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
DRB - Donald R. Burgess, Jr.

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.
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of vaporization

Enthalpy of vaporization

Δ_vapH = A exp(-αT_r) (1 − T_r)^β
    Δ_vapH = Enthalpy of vaporization (at saturation pressure) (kcal/mol)
    T_r = reduced temperature (T / T_c)

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Antoine Equation Parameters

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

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Enthalpy of sublimation

Temperature of phase transition

Enthalpy of phase transition

Entropy of phase transition

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:
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

C₆H₆N^- +  =

By formula: C₆H₆N^- + H⁺ = C₆H₇N

 +  = ( • )

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

 +  = ( • )

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

 +  = ( • )

By formula: K⁺ + C₆H₇N = (K⁺ • C₆H₇N)

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:
HL - Edward P. Hunter and Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
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 C₆H₇N⁺ (ion structure unspecified)

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₆H₆N^- +  =

By formula: C₆H₆N^- + H⁺ = C₆H₇N

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: Robert C. Dunbar

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

 +  = ( • )

By formula: K⁺ + C₆H₇N = (K⁺ • C₆H₇N)

 +  = ( • )

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

 +  = ( • )

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

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

• VAPOR (0.5 MICROLITER AT 150 C); NICOLET FTIR; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 CM^-1 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, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, Ion clustering 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.

Good, 1972
Good, W.D., Enthalpies of combustion of nine organic nitrogen compounds related to petroleum, J. Chem. Eng. Data, 1972, 17, 28-31. [all data]

Andon, Cox, et al., 1957
Andon, R.J.L.; Cox, J.D.; Herington, E.F.G.; Martin, J.F., The second virial coefficients of pyridine and benzene, and certain of their methyl homologues, Trans. Faraday Soc., 1957, 53, 1074. [all data]

Cox, Challoner, et al., 1954
Cox, J.D.; Challoner, A.R.; Meetham, A.R., The heats of combustion of pyridine and certain of its derivatives, J. Chem. Soc., 1954, 265-271. [all data]

Constam and White, 1903
Constam, E.J.; White, J., Physico-chemical investigations in the pyridine series, Am. Chem. J., 1903, 29, 1-49. [all data]

Messerly, Todd, et al., 1988
Messerly, J.F.; Todd, S.S.; Finke, H.L.; Good, W.D.; Gammon, B.E., Condensed-phase heat-capacity studies and derived thermodynamic properties for six cyclic nitrogen compounds, J. Chem. Thermodynam., 1988, 20, 209-224. [all data]

Messerly, Todd, et al., 1987
Messerly, J.F.; Todd, S.S.; Finke, H.L.; Gammon, B.E., Thermodynamic properties of organic nitrogen compounds that occur in shale oil and heavy petroleum-topical report, NIPER Report, 1987, 83, 37p. [all data]

Steele, Chirico, et al., 1986
Steele, W.V.; Chirico, R.D.; Collier, W.B.; Hossenlopp, I.A.; Nguyen, A.; Strube, M.M., Thermochemical and thermophysical properties of organic nitrogen compounds found in fossil materials, NIPER Report, 1986, 188, 112p. [all data]

Messerly, Todd, et al., 1988, 2
Messerly, J.F.; Todd, s.S.; Finke, H.L.; Good, W.D.; Gammon, B.E., Condensed-phase heat-capacity studies and derived thermodynamic properties for six cyclic nitrogen compounds, J. Chem. Thermodyn., 1988, 20, 209. [all data]

Soulard, Fillaux, et al., 1986
Soulard, L.; Fillaux, F.; Braathen, G.; Le Calve, N.; Pasquier, B., Rotational Dynamics of the Methyl Group in the 4-Methyl pyridine Crystal, Chem. Phys. Lett., 1986, 125, 41. [all data]

Majer and Svoboda, 1985
Majer, V.; Svoboda, V., Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]

Kobe and Mathews, 1970
Kobe, K.A.; Mathews, J.F., Critical Properties and Vapor Pressures of Some Organic Nitrogen and Oxygen Compounds, J. Chem. Eng. Data, 1970, 15, 182. [all data]

Ambrose and Grant, 1957
Ambrose, D.; Grant, D.G., The Critical Temperatures of Some Hydrocarbons and Pyridine Bases, Trans. Faraday Soc., 1957, 53, 771. [all data]

Chirico, Knipmeyer, et al., 1999
Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Steele, W.V., Thermodynamic properties of the methylpyridines. Part 2. Vapor pressures, heat capacities, critical properties, derived thermodynamic functions between the temperatures 250 K and 560 K, and equilibrium isomer distributions for all temperatures ≥250 K, The Journal of Chemical Thermodynamics, 1999, 31, 3, 339-378, https://doi.org/10.1006/jcht.1998.0451 . [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]

Osborn and Douslin, 1968
Osborn, Ann G.; Douslin, Donald R., Vapor pressure relations of 13 nitrogen compounds related to petroleum, J. Chem. Eng. Data, 1968, 13, 4, 534-537, https://doi.org/10.1021/je60039a024 . [all data]

Majer, Svoboda, et al., 1984
Majer, V.; Svoboda, V.; Lencka, M., Enthalpies of vaporization and cohesive energies of pyridine and isomeric methylpyridines, J. Chem. Thermodyn., 1984, 16, 1019-1024. [all data]

Herington and Martin, 1953
Herington, E.F.G.; Martin, J.F., Vapour pressures of pyridine and its homologues, Trans. Faraday Soc., 1953, 49, 154, https://doi.org/10.1039/tf9534900154 . [all data]

Herington and Martin, 1953, 2
Herington, E.F.G.; Martin, J.F., Vapour Pressures of Pyridine and its Homologues, Trans. Faraday Soc., 1953, 49, 154-162, https://doi.org/10.1039/tf9534900154 . [all data]

Meot-ner and Kafafi, 1988
Meot-ner, M.; Kafafi, S.A., Carbon Acidities of Aromatic Compounds, J. Am. Chem. Soc., 1988, 110, 19, 6297, https://doi.org/10.1021/ja00227a003 . [all data]

Kiefer, Zhang, et al., 1997
Kiefer, J.H.; Zhang, Q.; Kern, R.D.; Yao, J.; Jursic, B., Pyrolysis of Aromatic Azines: Pyrazine, Pyrimidine, and Pyridine, J. Phys. Chem. A, 1997, 101, 38, 7061, https://doi.org/10.1021/jp970211z . [all data]

DePuy, Kass, et al., 1988
DePuy, C.H.; Kass, S.R.; Bean, G.P., Formation and Reactions of Heteroaromatic Anions in the Gas Phase, J. Org. Chem., 1988, 53, 19, 4427, https://doi.org/10.1021/jo00254a001 . [all data]

Rodgers, 2001
Rodgers, M.T., Substituent Effects in the Binding of Alkali Metal Ions to Pyridines, Studied by Threshold Collision-Induced Dissociation and ab Initio Theory: The Methylpyridines, J. Phys. Chem. A, 2001, 105, 11, 2374, https://doi.org/10.1021/jp004055z . [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]

Zaretskii, Oren, et al., 1976
Zaretskii, Z.V.I.; Oren, D.; Kelner, L., Automatic method for the measurement of the electron impact ionization and appearance potentials, Appl. Spectrosc., 1976, 30, 366. [all data]

Stefanovic and Grutzmacher, 1974
Stefanovic, D.; Grutzmacher, H.F., The ionisation potential of some substituted pyridines, Org. Mass Spectrom., 1974, 9, 1052. [all data]

Distefano, Foffani, et al., 1971
Distefano, G.; Foffani, A.; Innorta, G.; Pignataro, S., Mass spectrometric study of transition metal complexes with ligands having nitrogen or sulphur as donor atom, Adv. Mass Spectrom., 1971, 5, 696. [all data]

Distefano, Foffani, et al., 1971, 2
Distefano, G.; Foffani, A.; Innorta, G.; Pignataro, S., Electron impact ionization potentials of some manganese, chromium and tungsten organometallic derivatives, Int. J. Mass Spectrom. Ion Phys., 1971, 7, 383. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Klasinc, Novak, et al., 1978
Klasinc, L.; Novak, I.; Scholz, M.; Kluge, G., Photoelektronenspektren substituierter Pyridine und Benzole und ihre Interpretation durch die CNDO/SWW-Methode, Croat. Chem. Acta, 1978, 51, 43. [all data]

Heilbronner, Hornung, et al., 1972
Heilbronner, E.; Hornung, V.; Pinkerton, F.H.; Thames, S.F., 31. Photoelectron spectra of azabenzenes and azanaphthalenes: III. The orbital sequence in methyl- and trimethylsilyl- substituted pyridines, Helv. Chim. Acta, 1972, 55, 289. [all data]

Palmer and Lossing, 1963
Palmer, T.F.; Lossing, F.P., Free radicals by mass spectrometry. XXX. Ionization potentials of anilino and 2-, 3-, and 4-pyridylmethyl radicals, J. Am. Chem. Soc., 1963, 85, 1733. [all data]

Handa, Utena, et al., 1986
Handa, T.; Utena, Y.; Yajima, H.; Ishii, T.; Morita, H., Excimer emission in protonated pyridine systems. 1. Fluorescence spectroscopy of protonated pyridine and its methyl derivatives in rigid glass solution at 77 K, J. Phys. Chem., 1986, 90, 2589-2596. [all data]

Notes

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

• Symbols used in this document:
  

  AE	Appearance energy
  Cp,liquid	Constant pressure heat capacity of liquid
  Pc	Critical pressure
  S°liquid	Entropy of liquid at standard conditions
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Ttrs	Temperature of phase transition
  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
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions
  ρc	Critical density

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