Standard molar enthalpies of formation, vapour pressures, and enthalpies of sublimation of 2-chloro-4-nitroaniline and 2-chloro-5-nitroaniline

• Tipo: Artigo em Revista Científica Internacional
• Data: 2003

Autores

da Silva, MAVR (Autor) FCUP; Lima, LMSS (Autor) Outra; Amaral, LMPF (Autor) Outra; Ana I M C L Lobo Ferreira (Autor) Outra; Jose R B Gomes (Autor) Outra

Revista

Título: Journal of Chemical Thermodynamics

Vol. 35

Páginas: 1343-1359

ISSN: 0021-9614

Editora: Elsevier

Indexação

ISI Web of Knowledge - 55 Citações

Scopus - 56 Citações

Outras Informações

ID Authenticus: P-000-FQP

DOI: 10.1016/s0021-9614(03)00109-5

Abstract (EN): The standard (p(o) = 0.1 MPa) molar enthalpies of formation for crystalline 2-chloro-4-nitroaniline and 2-chloro-5-nitroaniline were derived from the standard molar enthalpies of combustion, in oxygen, at the T = 298.15 K, measured by rotating bomb combustion calorimetry. The Knudsen mass-loss effusion technique was used to measure the vapour pressures of the crystals as function of temperature, and the standard molar enthalpies of sublimation, at T = 298.15 K, were derived by the Clausius-Clapeyron equation. Direct measurements of the standard molar enthalpies of sublimation, using Calvet microcalorimetry, for 2-chloro-4-nitroaniline and 2-chloro-5-nitroaniline confirmed the values derived from the Knudsen technique. [GRAPHICS] Additionally, standard enthalpies of formation were estimated by employing two different methodologies. One is based on the Cox scheme and the other one, much more accurate, is based on first-principles calculations. The theoretical calculations were performed at the AMI, B3LYP/6-31+G** and BP86/6-31+G** levels of theory. Estimated values are in good agreement with the reported experimental numbers.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 17