Barbital
- Formula: C8H12N2O3
- Molecular weight: 184.1925
- IUPAC Standard InChI: InChI=1S/C8H12N2O3/c1-3-8(4-2)5(11)9-7(13)10-6(8)12/h3-4H2,1-2H3,(H2,9,10,11,12,13)
- IUPAC Standard InChIKey: FTOAOBMCPZCFFF-UHFFFAOYSA-N
- CAS Registry Number: 57-44-3
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Other names: 2,4,6(1H,3H,5H)-Pyrimidinetrione, 5,5-diethyl-; Barbituric acid, 5,5-diethyl-; Barbitone; Deba; Diemal; Diethylbarbitone; Diethylbarbituric acid; Diethylmalonylurea; Dormonal; Ethylbarbital; Hypnogene; Malonal; Sedeval; Uronal; Veroletten; Veronal; Vesperal; 5,5-Diethylbarbituric acid; Verolettin; Kyselina 5,5-diethylbarbiturova; 5,5-Diethyl-2,4,6(1H,3H,5H)-pyrimidinetrione; NSC 31352; Metharbital M (nor)
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Condensed phase thermochemistry data
Go To: Top, Phase change 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 |
|---|---|---|---|---|---|
| ΔcH°solid | -986.2 | kcal/mol | Ccb | Fischer and Wrede, 1904 | Heat of combustion corrected for pressure |
| ΔcH°solid | -986.50 | kcal/mol | Ccb | Lemoult, 1904 |
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
AC - William E. Acree, Jr., James S. Chickos
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| Tfus | 463. | K | N/A | Kuffner, Bush, et al., 1957 | Uncertainty assigned by TRC = 4. K; not clear that this was measured by author; TRC |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔsubH° | 28.0 ± 0.1 | kcal/mol | ME | Ribeiro da Silva, Ribeiro da Silva, et al., 2009 | Based on data from 355. to 377. K.; AC |
Enthalpy of sublimation
| ΔsubH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 27.2 ± 0.1 | 366. | ME | Ribeiro da Silva, Ribeiro da Silva, et al., 2009 | Based on data from 355. to 377. K.; AC |
Enthalpy of fusion
| ΔfusH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
|---|---|---|---|---|
| 5.93 | 462. | DSC | Ribeiro da Silva, Ribeiro da Silva, et al., 2009 | AC |
| 5.970 | 462.6 | N/A | Chauvet, De Maury, et al., 1986 | AC |
References
Go To: Top, Condensed phase thermochemistry data, Phase change data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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]
Kuffner, Bush, et al., 1957
Kuffner, R.J.; Bush, M.T.; Bircher, L.J.,
Studies on the surface tension of aqueous barbituric acid solutions,
J. Am. Chem. Soc., 1957, 79, 1587-1589. [all data]
Ribeiro da Silva, Ribeiro da Silva, et al., 2009
Ribeiro da Silva, Maria das Dores M.C.; Ribeiro da Silva, Manuel A.V.; Freitas, Vera L.S.; Roux, Maria Victoria; Jiménez, Pilar; Temprado, Manuel; Dávalos, Juan Z.; Cabildo, Pilar; Claramunt, Rosa M.; Elguero, José,
Structural studies of cyclic ureas: 3. Enthalpy of formation of barbital,
The Journal of Chemical Thermodynamics, 2009, 41, 12, 1400-1407, https://doi.org/10.1016/j.jct.2009.06.018
. [all data]
Chauvet, De Maury, et al., 1986
Chauvet, A.; De Maury, G.; Terol, A.; Masse, J.,
Etude thermoanalytique de substances psychotropes,
Thermochimica Acta, 1986, 97, 143-159, https://doi.org/10.1016/0040-6031(86)87015-0
. [all data]
Notes
Go To: Top, Condensed phase thermochemistry data, Phase change data, References
- Symbols used in this document:
Tfus Fusion (melting) point ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfusH Enthalpy of fusion 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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