Mesoporous MOF Based on a Hexagonal Bipyramid Co8-Cluster: High Catalytic Efficiency on the Cycloaddition Reaction of CO2 with Bulky Epoxides

A mesoporous cobalt-based metal-organic framework (LCU606) was synthesized based on a hexagonal bipyramid Co-8(mu(4)-O) (3) cluster and an N, N, N ',N '- tetrakis-(4- benzoic acid)- 1,4-phenylenediamine ligand (H(4)TBAP). LCU-606 featuring large pore diameters of 21.7 angstrom and exposed Lewis-acid metal sites could serve as an excellent heterogeneous catalyst for CO2 cycloaddition reaction with various epoxide substrates under mild conditions (1 atm CO2, 60 degrees C, and solvent free). In particular, when extending the substrates to bulkier ones, LCU-606 still shows high catalytic efficiency on account of the large pore aperture. Also, LCU-606 demonstrates high recyclability and stability in consecutive catalytic runs. Therefore, the high efficiency, recyclability, and generality on CO2 catalytic cycloaddition make LCU-606 a very promising heterogeneous catalyst for CO2 chemical fixation.