Abstract (EN):
The standard molar enthalpies of formation of quinoxaline, quinazoline and phthalazine at 298.15 K in the gaseous state have been determined from the standard molar enthalpies of combustion of the crystalline solids and the respective enthalpies of sublimation: quinoxaline, 240.3 +/- 3.3 kJ mol(-1); quinazoline, 243.1 +/- 2.7 kJ mol(-1); phthalazine, 329.9 +/- 3.3 kJ mol(-1). Ab initio full geometry optimizations at the 3-21G and 6-31G* levels were also performed for these molecules. MP2/RHF/3-21G/3-21G energies were calculated for all isomers, and used to estimate their isodesmic resonance energies.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
4