Synthesis and thermochemical study of quinoxaline-N-oxides: enthalpies of dissociation of the N-O bond

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

Miguel L F Viveiros (Autor) Outra; Vera L S Freitas (Autor) FCUP; Nuno Vale (Autor) FCUP; Jose R B Gomes (Autor) Outra; Paula Gomes (Autor) FCUP; Maria D M C R Ribeiro da Silva (Autor) FCUP

Revista

Título: Journal of Physical Organic Chemistry

Vol. 25

Páginas: 420-426

ISSN: 0894-3230

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 8 Citações

Scopus - 8 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-002-APW

DOI: 10.1002/poc.1932

Abstract (EN): The synthesis of three new quinoxaline mono-N-oxides derivatives, namely, 2-tert-butoxycarbonyl-3-methylquinoxaline-N-oxide, 2-phenylcarbamoyl-3-ethylquinoxaline-N-oxide, and 2-carbamoyl-3-methylquinoxaline-N-oxide, from their corresponding 1,4-di-N-oxides is reported. Samples of these compounds were used for a thermochemical study, which allowed derivation of their gaseous standard molar enthalpies of formation, Delta fHmo(g), from their enthalpies of formation in the condensed phase, Delta fHmo(cr), determined by static bomb combustion calorimetry, and from their enthalpies of sublimation, Delta crgHmo, determined by Calvet microcalorimetry. Finally, combining the Delta fHmo(g) for the quinoxaline-N-oxides derived in this work with literature values for the corresponding 1,4-di-N-oxides and atomic oxygen, the bond dissociation enthalpies for cleavage of the first N-O bond in the di-N-oxides, DH1(NO), were obtained and compared with existing data. Copyright (c) 2011 John Wiley & Sons, Ltd.

Idioma: Inglês

Tipo (Avaliação Docente): Científica