The invertible electrochemical properties and thermal response of a series of gel-type ionic liquids based on polyoxometalates

Abstract

A series of vanadium-substituted Dawson-structure POM-type ionic liquids, [TEAPS]₇P₂W₁₇VO₆₂ and [TEAPS]₉P₂W₁₅V₃O₆₂, bearing sulfo-group grafted ammonium (TEAPS) cations and Dawson-type polyoxoanions have been formed which are reversible-thermal-response type gels. These gel-type compounds exhibit a phase transition from a quasi-solid gel phase to an isotropic sol phase. What's more, this series of hybrid compounds can undergo reversible electrochemical reactions in dimethyl formamide (DMF) owing to the reduction of the vanadium in POM anions as a simple anion, which is unlikely to happen in water solution because of water protonation.