Stability of [Bmim]PF6 as Catalyst-Solvent in Esterification Reactions

Abstract

Ionic liquids have been widely used as reaction media. However, investigations on the stability of an ionic liquid, [Bmim]PF₆ in the acid-catalysis reactions are scarcely reported. Taking the esterification of benzyl alcohol or cycloolefins with acetic acid as probe reactions, we investigated the effects of reaction conditions including substrates, atmosphere, water content, reaction temperature, reaction time and types of reactions on the stability of [Bmim]PF₆. Results indicate that inert atmosphere, dry environment, less reactive substrates and lower reaction temperature are beneficial for avoiding the decomposition of [Bmim]PF₆ but are of low conversion or poor selectivity.