Functional ionic liquids based on DABCO: Efficient catalysts for chemical fixation of CO 2 into cyclic carbonates

A series of basic functional ionic liquids were prepared from 1, 4-diazabicyclo [2.2.2] octane (DABCO) with various halogenated hydrocarbons, then these functional ionic liquids were used as catalysts for the chemical fixation of CO2 into cyclic carbonates and the influence of the structure of the ionic liquids was investigated. The results showed that the N atom active center, types of anions and hydrogen bond of the catalyst play a key role in the cycloaddition reaction of CO2 with epoxides to cyclic carbonates. Under mild reaction conditions (T = 100 °C, 1 atm CO2), the ionic liquid [DABCO-CH2CH2CH2OH] I showed the best catalytic effect, which has notable advantages such as high catalytic activity, eco-friendly, ease of work-up and convenient reuse.