Thymine

• Formula: C₅H₆N₂O₂
• Molecular weight: 126.1133
• IUPAC Standard InChI: InChI=1S/C5H6N2O2/c1-3-2-6-5(9)7-4(3)8/h2H,1H3,(H2,6,7,8,9) Copy

  
• IUPAC Standard InChIKey: RWQNBRDOKXIBIV-UHFFFAOYSA-N Copy
• CAS Registry Number: 65-71-4
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: 2,4(1H,3H)-Pyrimidinedione, 5-methyl-; Thymin; 2,4-Dihydroxy-5-methylpyrimidine; 5-Methyluracil; 5-Methyl-2,4-dioxypyrimidine; 5-Methyl-2,4(1H,3H)-pyrimidinedione
• 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
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
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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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

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 solid

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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of sublimation

Enthalpy of fusion

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:
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

Electron affinity determinations

Ionization energy determinations

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change 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.

Nabavian, Sabbah, et al., 1977
Nabavian, P.M.; Sabbah, R.; Chastel, R.; Laffitte, M., Thermodynamique de composes azotes. II. Etude thermochimique des acides aminobenzoiques, de la pyrimidine, de l'uracile et de la thymine., J. Chim. Phys., 1977, 74, 115-126. [all data]

Fischer and Wrede, 1904
Fischer, E.; Wrede, F., Uber die Verbrennungswarme einiger organischer Verbindungen, Sitzungsber. Dtsch. Akad. Wiss. Berlin Kl. Math. Phys. Tech., 1904, 687-715. [all data]

Lemoult, 1904
Lemoult, M.P., Remarques sur une serie recenie de determinations calorimetriques, Compt. Rend., 1904, 663-635. [all data]

Kilday, 1978
Kilday, M.V., Enthalpies of solution of the nucleic acid bases. 2. Thymine in water, J. Res., 1978, NBS 83, 529-537. [all data]

Alvarez and Biltonen, 1973
Alvarez, J.; Biltonen, R., Nucleic acid-solvent interactions: temperature dependence of the heat of solution of thymine in water and ethanol, Biopolymers, 1973, 12, 1815-1828. [all data]

Eykman, 1889
Eykman, J.F., Z. Phys. Chem., Stoechiom. Verwandtschaftsl., 1889, 4, 497. [all data]

Burkinshaw and Mortimer, 1984
Burkinshaw, Philip M.; Mortimer, Colin T., Enthalpies of sublimation of transition metal complexes, J. Chem. Soc., Dalton Trans., 1984, 1, 75, https://doi.org/10.1039/dt9840000075 . [all data]

Ferro, Bencivenni, et al., 1980
Ferro, D.; Bencivenni, L.; Teghil, R.; Mastromarino, R., Vapour pressures and sublimation enthalpies of thymine and cytosine, Thermochimica Acta, 1980, 42, 1, 75-83, https://doi.org/10.1016/0040-6031(80)87117-6 . [all data]

Nabavian, Sabbah, et al., 1977, 2
Nabavian, M.; Sabbah, R.; Chastel, R.; Laffitte, M., J. Chim. Phys.Phys.-Chim. Biol., 1977, 74, 115. [all data]

Teplitsky, Yanson, et al., 1980
Teplitsky, A.B.; Yanson, I.K.; Glukhova, O.T.; Zielenkiwicz, A.; Zielenkiewicz, W.; Wierzchowski, K.L., Thermochemistry of aqueous solutions of alkylated nucleic acid bases, Biophysical Chemistry, 1980, 11, 1, 17-21, https://doi.org/10.1016/0301-4622(80)85003-4 . [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]

Eykman, 1889, 2
Eykman, J.F., Zur kryoskopischen Molekulargewichtsbestimmung, Z. Physik. Chem., 1889, 4, 497-519. [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]

Hendricks, Lyapustina, et al., 1996
Hendricks, J.H.; Lyapustina, S.A.; de Clercq, H.L.; Snodgrass, J.T.; Bowen, K.H., Dipole bound, nucleic Acid Base Anions Studied via Negative Ion Photoelectron Spectroscopy, J. Chem. Phys., 1996, 104, 19, 7788, https://doi.org/10.1063/1.471482 . [all data]

Aflatooni, Gallup, et al., 1998
Aflatooni, K.; Gallup, G.A.; Burrows, P.D., Electron Attachment Energies of the DNA Bases, J. Phys. Chem., 1998, 102, 31, 6205, https://doi.org/10.1021/jp980865n . [all data]

Li, Bowen, et al., 2007
Li, X.; Bowen, K.H.; Haranczyk, M.; Bachorz, R.A.; Mazurkiewicz, K.; Rak, J.; Gutowski, M., Photoelectron spectroscopy of adiabatically bound valence anions of rare tautomers of the nucleic acid bases, J. Chem. Phys., 2007, 127, 17, 174309, https://doi.org/10.1063/1.2795719 . [all data]

Desfrancois, Abdoul-Carime, et al., 1999
Desfrancois, C.; Abdoul-Carime, H.; Carles, S.; Periquet, V.; Schermann, J.P.; Smith, D.M.A.; Adamowicz, L., Experimental and theoretical ab initio study of the influence of N-methylation on the dipole-bound electron affinities of thymine and uracil, J. Chem. Phys., 1999, 110, 24, 11876-11883, https://doi.org/10.1063/1.479175 . [all data]

Schiedt, Weinkauf, et al., 1998
Schiedt, J.; Weinkauf, R.; Neumark, D.M.; Schlag, E.W., Anion spectroscopy of uracil, thymine and the amino-oxo and amino-hydroxy tautomers of cytosine and their water clusters, Chem. Phys., 1998, 239, 1-3, 511-524, https://doi.org/10.1016/S0301-0104(98)00361-9 . [all data]

Desfrancois, Abdoul-Carime, et al., 1996
Desfrancois, C.; Abdoul-Carime, H.; Schermann, J.P., Electron Attachment to Isolated Nucleic Acid Bases, J. Chem. Phys., 1996, 104, 19, 7792, https://doi.org/10.1063/1.471484 . [all data]

Verkin, Sukodub, et al., 1976
Verkin, B.I.; Sukodub, L.F.; Yanson, I.K., Ionization potentials of nitrogenous bases of of nucleic acids, Dokl. Akad. Nauk SSSR, 1976, 228, 1452. [all data]

Lifschitz, Bergmann, et al., 1967
Lifschitz, C.; Bergmann, E.D.; Pullman, B., The ionization potentials of biological purines and pyrimidines, Tetrahedron Lett., 1967, 4583. [all data]

Dougherty, Wittel, et al., 1976
Dougherty, D.; Wittel, K.; Meeks, J.; McGlynn, S.P., Photoelectron spectroscopy of carbonyls. Ureas, uracils, and thymine, J. Am. Chem. Soc., 1976, 98, 3815. [all data]

Lauer, Schafer, et al., 1975
Lauer, G.; Schafer, W.; Schweig, A., Functional subunits in the nucleic acid bases uracil and thymine, Tetrahedron Lett., 1975, 45, 3939. [all data]

Hush and Cheung, 1975
Hush, N.S.; Cheung, A.S., Ionization potentials and donor properties of nucleic acid bases and related compounds, Chem. Phys. Lett., 1975, 34, 11. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  EA	Electron affinity
  Tfus	Fusion (melting) point
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔcH°solid	Enthalpy of combustion of solid 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
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions
  ΔvapH°	Enthalpy of vaporization at standard conditions

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