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
  • Reaction thermochemistry data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Gas phase ion energetics data
  • Ion clustering data
  • 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

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
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

C₅H₇N₂O₂⁺ +  = (C₅H₇N₂O₂⁺ • )

By formula: C₅H₇N₂O₂⁺ + C₅H₆N₂O₂ = (C₅H₇N₂O₂⁺ • C₅H₆N₂O₂)

 +  = ( • )

By formula: Na⁺ + C₅H₆N₂O₂ = (Na⁺ • C₅H₆N₂O₂)

 +  = ( • )

By formula: K⁺ + C₅H₆N₂O₂ = (K⁺ • C₅H₆N₂O₂)

IR 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: Coblentz Society, Inc.

Condensed Phase Spectrum

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Notice: Except where noted, spectra from this collection were measured on dispersive instruments, often in carefully selected solvents, and hence may differ in detail from measurements on FTIR instruments or in other chemical environments. More information on the manner in which spectra in this collection were collected can be found here.

Notice: Concentration information is not available for this spectrum and, therefore, molar absorptivity values cannot be derived.

Additional Data

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, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry 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.

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]

Meot-Ner (Mautner), 1979
Meot-Ner (Mautner), M., Ion Thermochemistry of Low Volatility Compounds in the Gas Phase. II. Intrinsic Basicities and Hydrogen Bonded Dimers of Nitrogen Heterocyclics and Nucleic Bases, J. Am. Chem. Soc., 1979, 101, 9, 2396, https://doi.org/10.1021/ja00503a027 . [all data]

Rodgers and Armentrout, 2000
Rodgers, M.T.; Armentrout, P.B., Noncovalent Interactions of Nucleic Acid Bases (Uracil, Thymine, and Adenine) with Alkali Metal Ions. Threshold Collision-Induced Dissociation and Theoretical Studies, J. Am. Chem. Soc., 2000, 121, 35, 8548, https://doi.org/10.1021/ja001638d . [all data]

Cerda and Wesdemiotis, 1996
Cerda, B.A.; Wesdemiotis, C., PAs of Peptides, J. Am. Chem. Soc., 1996, 118, 11884. [all data]

Notes

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• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  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
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔrS°	Entropy of reaction at standard conditions
  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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