Cytosine
- Formula: C4H5N3O
- Molecular weight: 111.1020
- IUPAC Standard InChIKey: OPTASPLRGRRNAP-UHFFFAOYSA-N
- 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
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Condensed phase thermochemistry data
Go To: Top, Reaction thermochemistry data, Gas phase ion energetics data, References, Notes
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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°solid | -52.89 ± 0.55 | kcal/mol | Ccb | Wilson, Watson, et al., 1979 | ALS |
ΔfH°solid | -56.27 ± 0.11 | kcal/mol | Ccr | Sabbah, Nabavian, et al., 1977 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -494.10 ± 0.48 | kcal/mol | Ccb | Wilson, Watson, et al., 1979 | ALS |
ΔcH°solid | -490.722 ± 0.088 | kcal/mol | Ccr | Sabbah, Nabavian, et al., 1977 | ALS |
Constant pressure heat capacity of solid
Cp,solid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
31.69 | 298. | Kilday, 1978 | DH |
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
By formula: C4H6N3O+ + C4H5N3O = (C4H6N3O+ • C4H5N3O)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 38.3 | kcal/mol | PHPMS | Meot-Ner (Mautner), 1979 | gas phase; M |
Quantity | Value | Units | Method | Reference | Comment |
ΔrS° | 37. | cal/mol*K | PHPMS | Meot-Ner (Mautner), 1979 | gas phase; M |
By formula: Na+ + C4H5N3O = (Na+ • C4H5N3O)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 42.3 | kcal/mol | CIDC | Cerda and Wesdemiotis, 1996 | RCD |
By formula: K+ + C4H5N3O = (K+ • C4H5N3O)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 26.3 | kcal/mol | CIDC | Cerda and Wesdemiotis, 1996 | RCD |
Gas phase ion energetics data
Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, References, Notes
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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Proton affinity (review) | 227.0 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 219. | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Electron affinity determinations
EA (eV) | Method | Reference | Comment |
---|---|---|---|
2.34 ± 0.10 | LPES | Li, Bowen, et al., 2007 | valence state of rare tautomer(H from NH2 to C5), inferred based on calculations; B |
0.2300 ± 0.0080 | LPES | Schiedt, Weinkauf, et al., 1998 | amino-oxo form. Dipole bound state; B |
0.0850 ± 0.0080 | LPES | Schiedt, Weinkauf, et al., 1998 | amino-hydroxy form. Dipole bound state; B |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
8.45 | PE | Dougherty, Younathan, et al., 1978 | LLK |
9.0 ± 0.1 | EI | Verkin, Sukodub, et al., 1976 | LLK |
8.9 ± 0.2 | EI | Lifschitz, Bergmann, et al., 1967 | RDSH |
8.94 ± 0.03 | PE | Hush and Cheung, 1975 | Vertical value; LLK |
References
Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry 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.
Wilson, Watson, et al., 1979
Wilson, S.R.; Watson, I.D.; Malcolm, G.N.,
Enthalpies of formation of solid cytosine, L-histidine, and uracil,
J. Chem. Thermodyn., 1979, 11, 911-912. [all data]
Sabbah, Nabavian, et al., 1977
Sabbah, R.; Nabavian, M.; Laffitte, M.,
Sur l'enthalpie de formation de la cytosine a 1'etat solide.,
C. R. Acad. Sci. Paris, 1977, 284, 953-954. [all data]
Kilday, 1978
Kilday, M.V.,
Enthalpies of solution of the nucleic acid bases. 3. Cytosine in water,
J. Res., 1978, NBS 83, 539-546. [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]
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]
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]
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]
Dougherty, Younathan, et al., 1978
Dougherty, D.; Younathan, E.S.; Voll, R.; Abdulnur, S.; McGlynn, S.P.,
Photoelectron spectroscopy of some biological molecules,
J. Electron Spectrosc. Relat. Phenom., 1978, 13, 379. [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]
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, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
Cp,solid Constant pressure heat capacity of solid EA Electron affinity ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°solid Enthalpy of formation of solid 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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