Enthalpies of Hydration of Alkenes. 1. The n-Hexenes

Article abstract of DOI:10.1021/ja00412a005

Alkenes undergo a rapid reaction with trifluoroacetic acid containing 0.25 M trifluoroacetic anhydride in the presence of a strong acid catalyst.The enthalpies of trifluoroacetolysis of the five n-hexenes were determined and were corrected to the enthalpies corresponding to the formation of the equilibrium mixture of 2-hexyl trifluoroacetate and 3-hexyl trifluoroacetate.The enthalpy difference between the latter was determined by measuring the equilibrium constant as a function of temperature.The trifluoroacetolysis data may be combined with the measured enthalpies of formation of the alkenes to derive more precise values for the latter.The enthalpies of reaction of water, 2-hexanol, and 3-hexanol with the reaction solvent were determined, and when combined with the other data lead to enthalpies of hydration of the alkenes and the enthalpies of formation of the alcohols.