Cooperative Capture of Uranyl Ions by a Carbonyl‐Bearing Hierarchical‐Porous Cu–Organic Framework

Abstract

To efficiently capture the toxic uranyl ions (UO 2 2+ ), an ew hierarchical micro-macroporous metal-organic framework was prepared under template-free conditions,f eaturing interconnected multi-nanocages bearing carbonyl groups derived from as emi-rigid ligand. The material exhibits an unusually high UO 2 2+ sorption capacity of 562 mg g À1 ,w hich occurs in an intriguing two-steps process,o nt he macroporebased crystal surface and in the inner nanocages.N otably,t he latter is attributed to the cooperative interplay of the shrinkage of the host porous framework induced by uranyl accommodation and the free carbonyl coordination sites,a ss hown by both single-crystal X-rayd iffraction and ar ed-shift of the infrared [O = U VI = O] 2+ antisymmetric vibration band.