Abstract

We revisit a possible mechanism for the thermal conversion of the title reaction, which appears to be driven by solvent effects by the ionic liquid (IL) dihydroxyethyldiethyl ammonium bromide Ne t 2 HE 2 Br . The effect of the solvent is discussed following two complementary models, namely, an explicit solvation approach, suggesting that the IL can be acting as a catalyst, and an implicit solvation model showing that stabilization/destabilization of the stationary points in the potential (free) energy, confirming that the epoxide ring opening is the rate determining step. The IL plays a key role in the activation of ethylene oxide, where the cation of the IL provides an efficient hydrogen bond to the epoxide moiety, together with a concerted approach of the Br? counterion. The activation step of the proposed mechanism is rationalized on the basis of a second order Fukui response function within the conceptual density functional theory. The proposed mechanism suggests a global third order reaction rate: order one in the cation and anion forming the IL structure and order one with respect to ethylene oxide. © 2025 Author(s).