Abstract (EN):
The standard (p degrees = 0.1 MPa) molar enthalpy of formation for solid and gaseous diphenic anhydride (2,2'-biphenyldicarboxylic anhydride, dibenz[c,e] oxepin-5,7-dione) was derived from the standard molar enthalpy of combustion, in oxygen, at T 298.15 K, measured by static bomb combustion calorimetry, and the standard molar enthalpy of sublimation, at T = 298.15 K, measured by Calvet microcalorimetry: -(258.4 +/- 4.9) kJ mol(-1). In addition, ab initio and density functional theory calculations have been performed at a variety of levels. The degree of aromaticity of diphenic anhydride is discussed in the context of other oxygen-containing (ring and keto) heterocycles and related carbocycles: this species is surprisingly destabilized.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Contacto:
jliebman@umbc.edu
Nº de páginas:
10