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

• Type: Article in International Scientific Journal
• Date: 2012

Authors

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

Journal

Title: Journal of Physical Organic Chemistry

Vol. 25

Pages: 420-426

ISSN: 0894-3230

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 8 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific