Trace water accelerating the CO2 cycloaddition reaction catalyzed by an indium–organic framework

Abstract

Based on a large skeleton ligand, 4,4′,4′′,4′′′-(1,4-phenylenebis(pyridine-4,2,6-triyl))tetrabenzoic acid (H₄L), a unique four-fold interpenetrated indium–organic framework {[NH₂(CH₃)₂][In(L)]·2DMF·H₂O}_n (V103) was synthesized and structurally characterized. This compound exhibits excellent solvent, pH, pressure, and thermal stability. Catalytic results indicate that V103 can serve as an efficient heterogeneous catalyst in a CO₂ cycloaddition reaction under mild conditions, and its catalytic activity shows no obvious inactivation even after five cycles. Particularly, the reaction is significantly accelerated with trace water as an additive, which is rather rare in MOF catalysis. These interesting results may provide new inspiration to develop MOF catalysts in heterogeneous reactions.