In situ cleavage and rearrangement synthesis of an easy-to-obtain and highly stable Cu(ii)-based MOF for efficient heterogeneous catalysis of carbon dioxide conversion

Abstract

Cycloaddition of carbon dioxide (CO₂) with epoxides into cyclic carbonates has been attracted substantial attentions for metal–organic frameworks based catalysis of CO₂ chemical fixation, not only due to the contributions that solving the environmental issue of the excessive emission CO₂, but also providing an effective pathway for the production of value-added fine chemicals. Herein, a Cu(II)-based metal–organic framework (1) was synthesized by the in situ cleavage and rearrangement of the N,N′-bis(4-picolinoyl)hydrazine ligand into an isonicotinate (INA) moiety as a connected node via solvothermal synthesis in high yields. This three-dimensional framework possesses infinite one-dimensional Cu–O double chains in a ladder-like arrangement with exposed metal centres, and can be highly stable up to at least 240 °C and in various solvents. Gas adsorption experiments reveal the good adsorption ability of 1 towards CO₂ with a high value of Q_st. Cycloaddition of CO₂ with epoxides could successfully occur by using 1 as an efficient heterogeneous catalyst, affording almost complete conversion and selectivity under solvent free conditions.