Experimental and computational thermochemistry of three nitrogen-containing heterocycles: 2-benzimidazolinone, 2-benzoxazolinone and 3-indazolinone

• Tipo: Artigo em Revista Científica Internacional
• Data: 2006

Autores

Morais, VMF (Autor) ICBAS; Miranda, MS (Autor) Outra; Matos, MAR (Autor) FCUP; Liebman, JF (Autor) Outra

Revista

Título: Molecular Physics

Vol. 104 Nº 22-24

Páginas: 325-334

ISSN: 0026-8976

Editora: Taylor & Francis

Indexação

ISI Web of Knowledge - 24 Citações

Scopus - 23 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Física

Outras Informações

ID Authenticus: P-004-N9H

DOI: 10.1080/00268970500290300

Abstract (EN): The standard molar enthalpies of combustion, sublimation, and formation of three nitrogen-containing heterocycles, namely, 2-benzimidazolinone, 2-benzoxazolinone and 3-indazolinone were determined calorimetrically. The standard (p degrees similar to 0.1 MPa) molar enthalpies of formation in the gas phase were derived from the standard molar enthalpies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry and from the standard molar enthalpies of sublimation at T 298.15 K, measured by Calvet microcalorimetry. Moller-Plesset calculations at the MP2 level and density functional calculations with the B3LYP functional and extended basis sets were also performed to determine the energetically preferred tautomeric form of the molecules. The results were qualitatively independent of the calculational level, where in general the DFT calculations were in better agreement with experiment than those from MP2. The gas and solid phase enthalpic differences between imines and amides, wherein -CH = N- is contrasted with -CONH-, have been studied and roughly constant values have been found.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10