Enthalpies of combustion, heat capacities, and enthalpies of vaporisation of 1-phenylimidazole and 1-phenylpyrazole

The standard (p(o) = 0.1 MPa) molar enthalpies of formation for liquid 1-ph enylimidazole (1PhIMI) and 1-phenylpyrazole (1IPhPYR) were derived from the standard molar enthalpies of combustion, in oxygen, at T = 298.15 K, Delta (c)H(m)(o), measured by static bomb combustion calorimetry. The molar heat capacities of both liquids were measured, in the temperature range (268 to 381) K, by differential scanning calorimetry. The standard molar enthalpies of vaporisation, at the temperature 298.15 K, Delta(l)(g)H(m)(o), were mea sured by Calvet microcalorimetry. The derived standard molar enthalpies of formation in the gaseous state are discussed comparatively. [GRAPHICS] (C) 2000 Academic Press.