Benzimidazolium‐Decorated Metalloporphyrin Molecule and Polymer: a Reliable Preparation Method and Application in Catalyzing the Cycloaddition Reaction of CO2and Epoxides

Abstract

AbstractDue to the synergistic effect of central metal and halide anion, cationic metalloporphyrins and derivatives exhibit outstanding catalytic activities for the cycloaddition reaction of epoxides and carbon dioxide. Herein, a generic strategy was developed to synthesize the benzimidazolium‐containing metalloporphyrin molecule and polymer. To demonstrate the method feasibility, we firstly synthesized the molecule1H, in which the benzimidazole groups were in‐site constructed by the cyclization of 5,10,15,20‐(4‐carboxyphenyl)‐porphyrin (H2TCPP) witho‐diaminobenzene (PEA). After post‐synthetic ionization and metallization, I−and Zn2+were introduced as the nucleophile and Lewis acid, respectively. The structure of1ZnILwas confirmed by single crystal X‐ray diffraction analysis. By using the similar conditions of model reaction,H2TCPPwas copolymerized with 1,2,4,5‐tetraaminobenzene (BTA) to prepare the polymerP‐1ZnIL. The prepared cationic molecule1ZnILand polymerP‐1ZnILshowed comparable activities in catalyzing the cycloaddition of carbon dioxide with epoxides to cyclic carbonates compared to the reported bifunctional catalysts based on metalloporphyrins.