Bisazole-Based Deep Eutectic Solvents for Efficient SO₂ Absorption and Conversion without Any Additives

Abstract

Four bisazole-based deep eutectic solvents (DESs) consisting of 1-ethyl-3-methylimidazolium chloride and azoles are prepared for the efficient absorption and conversion of SO2. These DESs can not only absorb SO2 up to 1.402 g/g at 20 °C and 1 bar but can also serve as catalysts for the cycloaddition of SO2 with epoxides. Moderate to good yields of cyclic sulfites are acquired for varied epoxides under mild conditions (60 °C and 1 bar of SO2) without any additives.