Experimental thermochemical study of the enthalpies of formation and sublimation of isonicotinamide, picolinamide, nicotinamide, isonicotinamide N-oxide, and nicotinamide N-oxide. The dissociation enthalpies of the N-O bonds

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

da Silva, MDMCR (Autor) FCUP; Goncalves, JM (Autor) FCUP; Ferreira, SCC (Autor) Outra; da Silva, LCM (Autor) Outra; Sottomayor, MJ (Autor) FCUP; Pilcher, G (Autor) Outra; Acree, WE (Autor) Outra; Roy, LE (Autor) Outra

Revista

Título: Journal of Chemical Thermodynamics

Vol. 33

Páginas: 1263-1275

ISSN: 0021-9614

Editora: Elsevier

Indexação

ISI Web of Knowledge - 32 Citações

Scopus - 36 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia mecânica

Outras Informações

ID Authenticus: P-000-T5A

DOI: 10.1006/jcht.2001.0839

Abstract (EN): The standard (p(o) = 0.1 MPa) molar enthalpies of combustion in oxygen, at T = 298.15 K, for crystalline picolinamide (2-NH2COPy), nicotinamide (3-NH2COPy), isonicotinamide (4-NH2COPy), nicotinamide N-oxide (3-NH2COPyNO), and isonicotinamide N-oxide (4-NH2COPyNO) were measured by static-bomb calorimetry. These values were used to derive the standard molar enthalpies of formation of the crystalline compounds. The standard molar enthalpies of sublimation, at T = 298.15 K, for the three pyridinecarboxamide isomers were measured by microcalorimetry and the standard molar enthalpies of sublimation for the two pyridinecarboxamide N-oxide compounds were measured by a mass-loss effusion technique. From the enthalpies of formation of the gaseous compounds, the molar dissociation enthalpies D-m(o) of the (N+-O-) covalent bonds were derived. Comparison has been made with D-m(o) (N-O) values in pyridine N-oxide derivatives. [GRAPHICS] (C) 2001 Academic Press.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 13