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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- Other data available:
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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
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 |
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 by: William E. Acree, Jr., James S. Chickos
Enthalpy of sublimation
ΔsubH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
27.0 ± 0.96 | 442. | TE | Brunetti and Piacente, 1999 | Based on data from 392. to 493. K. |
26.60 ± 0.07 | 294. to 438. | GS | Zielenkiewicz, Perlovich, et al., 1999 | |
29.47 ± 0.41 | 440. | ME | Soldatova, Kabo, et al., 1990, 3 | Based on data from 404. to 479. K. |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference |
---|---|---|
4.988 | 526.4 | Roux, Temprado, et al., 2008 |
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 by: John E. Bartmess
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
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 |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 327.3 ± 2.0 | kcal/mol | IMRE | Cumming and Kebarle, 1978 | gas phase; Acid: barbituric acid |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry 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]
Brunetti and Piacente, 1999
Brunetti, B.; Piacente, V.,
Sublimation Enthalpies Study for Barbituric, Tiobarbituric, and Selenobarbituric Acids from Their Vapor Pressure Measurements,
J. Chem. Eng. Data, 1999, 44, 4, 809-812, https://doi.org/10.1021/je980300k
. [all data]
Zielenkiewicz, Perlovich, et al., 1999
Zielenkiewicz, X.; Perlovich, G.L.; Wszelaka-Rylik, M.,
Journal of Thermal Analysis and Calorimetry, 1999, 57, 1, 225-234, https://doi.org/10.1023/A:1010179814511
. [all data]
Soldatova, Kabo, et al., 1990, 3
Soldatova, T.V.; Kabo, G.Ya.; Kozyro, A.A.; Frenkel, M.L.,
Thermodynamic properties and tautomerism of barbituric acid,
Zh. Fiz. Khim., 1990, 64, 2, 336. [all data]
Roux, Temprado, et al., 2008
Roux, Maria Victoria; Temprado, Manuel; Notario, Rafael; Foces-Foces, Concepcion; Emel'yanenko, Vladimir N.; Verevkin, Sergey P.,
Structure-Energy Relationship in Barbituric Acid: A Calorimetric, Computational, and Crystallographic Study,
J. Phys. Chem. A, 2008, 112, 32, 7455-7465, https://doi.org/10.1021/jp803370u
. [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, Phase change data, Reaction thermochemistry 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 ΔfusH Enthalpy of fusion ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔsubH Enthalpy of sublimation - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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