Pillar[5]arene-segregated ion pairs for enhanced cycloaddition of epoxides with CO 2 .

A supramolecular approach using a polyviologen-pillar[5]arene complex as segregated ion pairs was shown to be highly efficient for the conversion of CO 2 with epoxides into cyclic carbonates without the need for metals or solvents. The enhanced catalytic performance was achieved by cooperative ion pair segregation and CO 2 fixation.