Temperature and Pressure Effects on the Reversible Reaction of a Parent Phenol (GH) Corresponding to Galvinoxyl with Aliphatic Amines

Article abstract of DOI:10.1246/bcsj.65.2437

The effects of temperature and pressure on the reversible reaction between GH and aliphatic amines in acetonitrile have been studied spectrophotometrically.The formation of the free ions rather than that of ion pairs has been confirmed by the modified Benesi-Hildebrand (B-H) plot.From the plot the equilibrium constants were estimated.From the temperature dependence of the equilibrium constant (K), the heat and entropy of reactions were estimated to be: (ΔH⁰)_av=-44.5 kJ mol^-1, and (ΔS⁰)_av=-193 J K^-1 mol^-1.From the pressure dependence of K the reaction volume (ΔV⁰)_av was estimated to be -40 dm³ mol^-1.When unbranched primary amines were used, a side reaction took place for which an explanation has been given.