A new Mn(Ⅱ)-based metal-organic framework: synthesis, characterization, ferrimagnetic behavior and catalytic conversion of CO2 to cyclic carbonates

Abstract

A new three-dimensional (3D) metal–organic framework (MOF) [Mn3(bqca)2(DMF)4]n (1) is constructed based on a tricarboxylate ligand 2,3-di-(4-carboxyphenyl)-quinoline-6-carboxylic acid (H3bqca) through solvothermal reaction. The structure, composition and stability of the complex were fully characterized by single crystal X-ray diffraction, powder X-ray diffraction, infrared spectrum and thermogravimetric analysis. The results show that 1 has a 3D microporous framework and exhibits high thermal stability up to 450 ℃. Direct-current magnetic susceptibility reveals that 1 is a rare ferrimagnetic homospin system. Importantly, 1 can effectively catalyze the cycloaddition reaction of CO2 with epoxides to generate cyclic carbonates with high yields and selectivity, and it can also be recycled at least five times without a noticeable change in catalytic efficiency.