Synthesis, characterization and thermochemical properties of N-acyl-N ',N '-diethylthioureas

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

Autores

da Silva, MAVR (Autor) FCUP; da Silva, MDMCR (Autor) FCUP; da Silva, LCM (Autor) Outra; Dietze, F (Autor) Outra; Hoyer, E (Autor) Outra; Beyer, L (Autor) Outra; Schroder, B (Autor) Outra; Damas, AM (Autor) ICBAS; Liebman, JF (Autor) Outra

Revista

A Revista está pendente de validação pelos Serviços Administrativos.

Título: JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2

Páginas: 2174-2178

ISSN: 1472-779X

Indexação

ISI Web of Knowledge - 15 Citações

Scopus - 15 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-000-SXZ

DOI: 10.1039/b104709b

Abstract (EN): Three N-acyl-N',N'-diethylthioureas, RCONHCSNEt2. R = Pr-1, Bu-1, Bu-1, have been prepared and characterised. The standard (p(o) = 0.1 MPa) molar enthalpies of combustion in oxygen of the three crystalline compounds, at T = 298.15 K. have been measured by rotating bomb-combustion calorimetry. and the standard molar enthalpies of sublimation of the compounds by microcalorimetry. These values were used to derive the standard molar enthalpies of formation of the compounds in their crystalline and gaseous phases, respectively. The derived standard molar enthalpies of formation in the gaseous state are discussed comparatively. Acid constants and some complex stabilities have been measured pH-potentiometrically in dioxane-water mixture. The crystal structure of N,N-diethyl-N'-isovaleroyl-thiourea is presented and shows a delocalization of the pi electrons of the C=S group over the carbon-amine nitrogen bond. CS-NEt2 stabilising the molecule, in accordance with the thermochemical results.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 5