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Calorimetric and computational study of 2H-1, 4-benzoxazin-3(4H)-one and of related species |
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| Authors: | M. Agostinha R. Matos Margarida S. Miranda Victor M. F. Morais Joel F. Liebman |
| Affiliation: | 1. Centro de Investiga??o em Química , Departamento de Química , Faculdade de Ciências da Universidade do Porto , Rua do Campo Alegre, 687, P-4169-007 Porto, Portugal marmatos@fc.up.pt;3. Centro de Investiga??o em Química , Departamento de Química , Faculdade de Ciências da Universidade do Porto , Rua do Campo Alegre, 687, P-4169-007 Porto, Portugal;4. Centro de Investiga??o em Química , Departamento de Química , Faculdade de Ciências da Universidade do Porto , Rua do Campo Alegre, 687, P-4169-007 Porto, Portugal;5. Instituto de Ciências Biomdicas Abel Salazar , ICBAS, Universidade do Porto , P-4099-003 Porto, Portugal;6. Department of Chemistry and Biochemistry , University of Maryland , Baltimore County, Baltimore, MD 21250, USA |
| Abstract: | The standard molar enthalpy of formation in the gas phase of 2H-1,4-benzoxazin-3(4H)-one was derived from the standard energy of combustion determined by static bomb combustion calorimetry in oxygen atmosphere and from the standard sublimation enthalpy determined by Calvet microcalorimetry. In addition, we report the results of a systematic theoretical study of the keto and enol tautomers in benzoxazinones and diones using density functional theory. The keto tautomers are computed to be more stable than the enols. Tautomerization energies are reported. |
| Keywords: | 2H-1,4-benzoxazin-3(4H)-one and related diones and enols Calorimetry DFT calculations Enthalpies of combustion and formation Phase change enthalpies Tautomerization |