Thermochemical properties of N-heterocyclic compounds I. Enthalpies of combustion, vapour pressures and enthalpies of sublimation, and enthalpies of formation of pyrazole, imidazole, indazole, and benzimidazole

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

“…The experimental results for the enthalpies of formation of 1-phenylimidazole and 1-phenylpyrazole obtained in the present work are consistent with this; 1-phenylimidazole being more stable by (26.7 ± 6.2) kJ · mol −1 . Considering the following hypothetical redistribution reactions involving the pairs imidazole/N -alkyl(aryl) imidazole and benzene/alkyl(aryl) benzene: and using the values for the standard molar enthalpies of formation, in the gaseous state, of imidazole (132.9 ± 0.6) kJ · mol −1 , (1) biphenyl (181.4 ± 2.0) kJ · mol −1 , (19) benzene (82.6 ± 0.7) kJ · mol −1 , (19) ethylbenzene ( This fact is also valid, within the experimental uncertainties, for the identical hypothetical redistribution reactions (4) and (5) …”

“…(1)(2)(3)(4) However, thermochemical studies of substituted nitrogen azole derivatives are still very scarce, and this paper is a contribution to the thermochemical study of N -substituted derivatives of imidazole and pyrazole. Azoles, like imidazoles and pyrazoles, are aromatic rings, which can be linked to substituents by a nitrogen atom.…”

Structural effects on the thermochemical properties of cycloalkanones. III. Enthalpy of combustion, vapour pressures, and enthalpy of sublimation, and standard enthalpy of formation in the gaseous phase of pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione

“…(27) The nitric acid content of the bomb liquid was determined by titration with 0.1 mol·dm −3 NaOH (aq). The corrections for nitric acid formation were based on −59.7 kJ·mol −1 for the standard molar energy of formation of 0.1 mol·dm −3 HNO 3 (aq) from N 2 (g), O 2 (g), and H 2 O(l).…”

Structural effects on the thermochemical properties of cycloalkanones II. Enthalpy of combustion, vapour pressures, enthalpy of sublimation, and standard molar enthalpy of formation in the gaseous phase of cyclopentadecanone

“…From the experimental results of this work, the standard molar enthalpies of combustion, sublimation, and formation in the crystalline and gaseous state at the temperature 298. 15 …”