Experimental and Computational Studies on the Structural and Thermodynamic Properties of Two Sulfur Heterocyclic Keto Compounds

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Vera L S Freitas (Autor) Outra; Jose R B Gomes (Autor) Outra; Luis Gales (Autor) ICBAS; Ana M Damas (Autor) ICBAS; Maria D M C R Ribeiro da Silva (Autor) FCUP

Revista

Título: Journal of Chemical & Engineering Data

Vol. 55 Nº 1

Páginas: 5009-5017

ISSN: 0021-9568

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 23 Citações

Scopus - 23 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia química

Outras Informações

ID Authenticus: P-003-1FJ

DOI: 10.1021/je100603q

Abstract (EN): The present work reports the standard (p degrees = 0.1 MPa) molar enthalpies of formation in the gaseous phase of thioxanthone, (91.9 +/- 2.4) kJ.mol(-1), and tetrahydrothio-gamma-pyrone, (-164.6 +/- 2.0) kJ.mol(-1), at T = 298.15 K, derived from their standard molar energies of combustion and standard molar enthalpies of sublimation, measured by rotating-bomb combustion calorimetry and by the vacuum drop microcalorimetric technique, respectively. For comparison purposes, we performed additional standard ab initio molecular orbital calculations, using the G3(MP2)//B3LYP composite procedure, which were used for the calculation of the enthalpies of several homodesmotic reactions, allowing us to extract the standard molar enthalpies of formation, in the gaseous phase, of the two heterocycles considered in this work. The calculated results are in excellent agreement with the experimental data. The three-dimensional structure of the crystal tetrahydrothio-gamma-pyrone was also determined by X-ray crystallography.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9