Effect of fluorine substitution, pressure and temperature on the tautomeric equilibria of acetylacetonate β-diketones

Abstract

The equilibrium between the keto and enol tautomers of acetylacetone, trifluoroacetylacetone and hexafluoroacetylacetone in the neat liquid state and dissolved in supercritical fluid carbon dioxide have been studied, as a function of pressure and temperature, by ¹ H NMR. This allows determination of the thermodynamic parameters, ΔH and ΔS, for the keto–enol equilibrium. The observed trends are well correlated with extraction results for this class of compounds.