Cytosine

• Formula: C₄H₅N₃O
• Molecular weight: 111.1020
• IUPAC Standard InChI: InChI=1S/C4H5N3O/c5-3-1-2-6-4(8)7-3/h1-2H,(H3,5,6,7,8) Copy

  
• IUPAC Standard InChIKey: OPTASPLRGRRNAP-UHFFFAOYSA-N Copy
• CAS Registry Number: 71-30-7
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: 2(1H)-Pyrimidinone, 4-amino-; Cyt; Cytosinimine; 4-Amino-2(1H)-pyrimidinone; 4-Amino-2-hydroxypyrimidine; 4-Amino-2(1H)pyrimidone; 4-Amino-2-oxypyrimidine
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Gas phase ion energetics data
  • Ion clustering data
  • IR Spectrum
  • 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

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:
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Enthalpy of sublimation

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

C₄H₆N₃O⁺ +  = (C₄H₆N₃O⁺ • )

By formula: C₄H₆N₃O⁺ + C₄H₅N₃O = (C₄H₆N₃O⁺ • C₄H₅N₃O)

 +  = ( • )

By formula: Na⁺ + C₄H₅N₃O = (Na⁺ • C₄H₅N₃O)

 +  = ( • )

By formula: K⁺ + C₄H₅N₃O = (K⁺ • C₄H₅N₃O)

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, Phase change data, Reaction thermochemistry data, 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.

Sabbah, 1980
Sabbah, R., Thermodynamics of nitrogen compounds. V. Thermochemical study of cytosine, Thermochim. Acta, 1980, 35, 73-77. [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]

de Barros, Medina, et al., 2006
de Barros, A.L.F.; Medina, A.; Zappa, F.; Pereira, J.M.; Bessa, E.; Martins, M.H.P.; Coelho, L.F.S.; Wolff, W.; de Castro Faria, N.V., A simple experimental arrangement for measuring the vapour pressures and sublimation enthalpies by the Knudsen effusion method: Application to DNA and RNA bases, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2006, 560, 2, 219-223, https://doi.org/10.1016/j.nima.2006.01.026 . [all data]

Zielenkiewicz, Wszelaka-Rylik, et al., 1998
Zielenkiewicz, A.; Wszelaka-Rylik, M.; Poznanski, J.; Zielenkiewicz, W., Journal of Solution Chemistry, 1998, 27, 3, 235-243, https://doi.org/10.1023/A:1022636218154 . [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]

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

Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  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

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