Experimental and computational thermodynamic study of ortho-, meta-, and para-methylbenzamide

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

Autores

Ana R R P Almeida (Autor) Outra; Agostinha A R Matos (Autor) FCUP; Manuel J S Monte (Autor) FCUP; Victor M F Morais (Autor) ICBAS

Revista

Título: Journal of Chemical Thermodynamics

Vol. 47

Páginas: 81-89

ISSN: 0021-9614

Editora: Elsevier

Indexação

ISI Web of Knowledge - 15 Citações

Scopus - 15 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia mecânica

Outras Informações

ID Authenticus: P-002-BY3

DOI: 10.1016/j.jct.2011.09.024

Abstract (EN): The Knudsen mass-loss effusion technique was used to measure the vapour pressures of the three crystalline isomers of methylbenzamide. From the temperature dependence of the vapour pressures, the standard molar enthalpies of sublimation and the enthalpies of the intermolecular hydrogen bonds N-H center dot center dot center dot O were calculated. The temperature and molar enthalpy of fusion of the studied isomers were measured using differential scanning calorimetry. The values of the standard (p degrees = 0.1 MPa) molar enthalpy of formation in the crystalline phase, at T = 298.15 K, of the compounds studied were derived from their standard massic energies of combustion measured by static-bomb combustion calorimetry. From the experimental values, the standard molar enthalpies of formation in the gaseous phase, at T = 298.15 K, were calculated and compared with the values estimated by employing computational calculations that were conducted using different quantum chemical methods: G3( MP2), G3, and CBS-QB3. Good agreement between experimental and theoretical results is verified. The aromaticity of the compounds has been evaluated through nucleus independent chemical shifts (NICS) calculations.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9