Barbituric acid
- Formula: C4H4N2O3
- Molecular weight: 128.0862
- IUPAC Standard InChIKey: HNYOPLTXPVRDBG-UHFFFAOYSA-N
- CAS Registry Number: 67-52-7
- Chemical structure:
This structure is also available as a 2d Mol file - Species with the same structure:
- Other names: 2,4,6(1H,3H,5H)-Pyrimidinetrione; Malonylurea; Pyrimidinetrione; Urea, N,N'-(1,3-dioxo-1,3-propanediyl)-; 2,4,6-Pyrimidinetriol; 2,4,6-Trihydroxypyrimidine; 2,4,6-Trioxohexahydropyrimidine; 6-Hydroxyuracil; 2,4,6-Pyrimidinetrione(1H,3H,5H)
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Gas phase thermochemistry data
Go To: Top, Condensed phase 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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -121.8 | kcal/mol | Ccb | Soldatova, Kabo, et al., 1990 |
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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°solid | -151.70 ± 0.68 | kcal/mol | Ccb | Soldatova, Kabo, et al., 1990 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -361.16 ± 0.68 | kcal/mol | Ccb | Soldatova, Kabo, et al., 1990 | ALS |
ΔcH°solid | -358.89 | kcal/mol | Ccb | Lemoult, 1904 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°solid,1 bar | 37.60 | cal/mol*K | N/A | Soldatova, Kabo, et al., 1990, 2 | DH |
S°solid,1 bar | 37.67 | cal/mol*K | N/A | Koshchenko, Ismailov, et al., 1985 | Extrapolated below 90 K.; DH |
Constant pressure heat capacity of solid
Cp,solid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
33.72 | 298.15 | Soldatova, Kabo, et al., 1990, 2 | T = 10 to 450 K. Cp(c) = 25.67 + 0.3361T + 3.382x10-4T2 - 5.64x10-7T3 J/mol*K (200 to 450 K).; DH |
33.72 | 298.15 | Koshchenko, Ismailov, et al., 1985 | T = 90 to 300 K.; DH |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Condensed phase 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 compiled as indicated in comments:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.20 | PE | Dougherty, Younathan, et al., 1978 | LLK |
De-protonation reactions
C4H3N2O3- + =
By formula: C4H3N2O3- + H+ = C4H4N2O3
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 335.1 ± 2.9 | kcal/mol | G+TS | Cumming and Kebarle, 1978 | gas phase; Acid: barbituric acid; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 327.3 ± 2.0 | kcal/mol | IMRE | Cumming and Kebarle, 1978 | gas phase; Acid: barbituric acid; B |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase 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.
Soldatova, Kabo, et al., 1990
Soldatova, T.V.; Kabo, G.Ya.; Kozyro, A.A.; Frenkel, M.L.,
Thermodynamic properties and tautomerism of barbituric acid,
Russ. J. Phys. Chem. (Engl. Transl.), 1990, 64, 177-180. [all data]
Lemoult, 1904
Lemoult, M.P.,
Remarques sur une serie recenie de determinations calorimetriques,
Compt. Rend., 1904, 663-635. [all data]
Soldatova, Kabo, et al., 1990, 2
Soldatova, T.V.; Kabo, G.Ya.; Kozyro, A.A.; Frenkel, M.L.,
Thermodynamic properties and tautomerism of barbituric acid,
Zhur. Fiz. Khim., 1990, 64(2), 336-343. [all data]
Koshchenko, Ismailov, et al., 1985
Koshchenko, V.I.; Ismailov, T.S.; Potekhin, V.M.; Razikov, K.Kh.,
Thermodynamic functions of barbituric acid,
Zhur. Prikl. Khim. (Leningrad), 1985, 58, 445-456. [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]
Cumming and Kebarle, 1978
Cumming, J.B.; Kebarle, P.,
Summary of gas phase measurements involving acids AH. Entropy changes in proton transfer reactions involving negative ions. Bond dissociation energies D(A-H) and electron affinities EA(A),
Can. J. Chem., 1978, 56, 1. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
Cp,solid Constant pressure heat capacity of solid S°solid,1 bar Entropy of solid at standard conditions (1 bar) ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°solid Enthalpy of formation of solid at standard conditions ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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