Thermochemical studies of phthalimide and two N-alkylsubstituted phthalimides (ALKYL=ETHYL AND n-PROPYL)

摘要

The standard ( p(0)= 0.1 MPa) molar enthalpies of formation, Delta H-f(m)0, for crystalline phthalimides: phthalimide, N-ethylphthalimide and N-propylphthalimide were derived from the standard molar enthalpies of combustion, in oxygen, at the temperature 298.15 K, measured by static bomb-combustion calorimetry, as, respectively, - ( 318.0 +/- 1.7), - (350.1 +/- 2.7) and - ( 377.3 +/- 2.2) kJ mol(-1). The standard molar enthalpies of sublimation, Delta H-8(cr)m(0), at T=298.15 K were derived by the Clausius-Clapeyron equation, from the temperature dependence of the vapour pressures for phthalimide, as (106.9 +/- 1.2) kJ mol(-1) and from high temperature Calvet microcalorimetry for phthalimide, N-ethylphthalimide and N-propylphthalimide as, respectively, (106.3 +/- 1.3), (91.0 +/- 1.2) and (98.2 +/- 1.4) kJ mol(-1).