Experimental and computational study of the energetics of hydantoin and 2-thiohydantoin

• Tipo: Artigo em Revista Científica Internacional
• Data: 2013

Autores

Ana L R Silva (Autor) Outra; Alvaro Cimas (Autor) Outra; Nuno Vale (Autor) FCUP; Paula Gomes (Autor) FCUP; Manuel J S Monte (Autor) FCUP; Maria D M C R Ribeiro da Silva (Autor) FCUP

Revista

Título: Journal of Chemical Thermodynamics

Vol. 58

Páginas: 158-165

ISSN: 0021-9614

Editora: Elsevier

Indexação

ISI Web of Knowledge - 16 Citações

Scopus - 16 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-002-0CH

DOI: 10.1016/j.jct.2012.10.010

Abstract (EN): This work reports an experimental and a theoretical study of two imidazolidine derivatives, hydantoin (CAS No. 461-72-3) and 2-thiohydantoin (CAS No. 503-87-7). The standard (p degrees = 0.1 MPa) molar energies of combustion of hydantoin and 2-thiohydantoin were measured by static and rotating bomb combustion calorimetry, respectively. The standard molar enthalpies of sublimation, at T = 298.15 K, were derived from the temperature dependence of the vapour pressures of these compounds, measured by the Knudsen-effusion technique, and from high temperature Calvet microcalorimetry. The conjugation of these experimental results enables the calculation of the standard molar enthalpies of formation in the gaseous state, at T = 298.15 K, which are discussed in terms of structural contributions. We have also estimated the gas-phase enthalpy of formation from high-level ab initio molecular orbital calculations at the G3MP2B3 level of theory, being the computed values in good agreement with the experimental ones. Furthermore, this composite approach was also used to obtain information about the gas-phase basicities, proton and electron affinities and adiabatic ionization enthalpies.

Idioma: Inglês

Tipo (Avaliação Docente): Científica