Energetics of Coumarin and Chromone

• Tipo: Artigo em Revista Científica Internacional
• Data: 2009

Autores

Agostinha A R Matos (Autor) FCUP; Clara C S Sousa (Autor) FCUP; Margarida S Miranda (Autor) FCUP; Victor M F Morais (Autor) ICBAS; Joel F Liebman (Autor) Outra

Revista

Título: Journal of Physical Chemistry B

Vol. 113

Páginas: 11216-11221

ISSN: 1520-6106

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 25 Citações

Scopus - 22 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-003-GS5

DOI: 10.1021/jp9026942

Abstract (EN): Condensed phase standard (p degrees = 0.1 MPa) molar enthalpies of formation for coumarin and chromone were derived from the standard molar enthalpies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The standard molar enthalpies of sublimation, at T = 298.15 K, were measured by Calvet microcalorimetry. Combining these values, the following enthalpies of formation in the gas phase, at T = 298.15 K, were then derived: coumarin, -(163.4 +/- 3.3) kJ(.)mol(-1), and chromone, -(126.1 +/- 2.5) kJ(.)mol(-1). The temperatures of fusion, T(fusion), and fusion enthalpies, at T = T(fusion), were also reported. Additionally, theoretical calculations were done using different methods: DFT/B3LYP, MCCM (MC-UT/3 and MC-QCISD/3), and also the more accurate G3MP2 method. Good agreement between experimental and theoretical data was achieved. Some correlations between structure and energy were also made, and the aromaticity of the compounds was evaluated by the nucleus independent chemical shifts (NICS).

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6