Thermochemistry of some methoxypyridines

Abstract

The standard (po=0.1MPa) molar enthalpies of formation, at T=298.15K, for the liquids 2-methoxypyridine, 4-methoxypyridine and 2,6-dimethoxypyridine were determined by static bomb combustion calorimetry. The standard molar enthalpies of vaporization, at T=298.15K, were measured by Calvet microcalorimetry. The standard (po=0.1MPa) molar enthalpies of formation of the three compounds studied, in the gaseous phase, at T=298.15K have been derived from the corresponding standard molar enthalpies of formation in the liquid phase and the standard molar enthalpies of vaporization, yielding ((−42.7±1.9), (−18.2±1.8) and (−233.5±1.8))kJ·mol−1, for 2-methoxypyridine, 4-methoxypyridine and 2,6-dimethoxypyridine, respectively.