Mesoporous MOF Based on a Hexagonal Bipyramid Co 8 -Cluster: High Catalytic Efficiency on the Cycloaddition Reaction of CO 2 with Bulky Epoxides.

A mesoporous cobalt-based metal-organic framework (LCU-606) was synthesized based on a hexagonal bipyramid Co 8 (μ 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 Å and exposed Lewis-acid metal sites could serve as an excellent heterogeneous catalyst for CO 2 cycloaddition reaction with various epoxide substrates under mild conditions (1 atm CO 2 , 60 °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 CO 2 catalytic cycloaddition make LCU-606 a very promising heterogeneous catalyst for CO 2 chemical fixation.