摘要
Tailored design of organic linkers or metal nodes can introduce desirable functionalities into metal-organic cages(MOCs),significantly expanding their potential applications.In this study,we present a viable approach for engineering acyl-type metal nodes to create interior oxygen-rich sites within MOCs,enabling specific recognition of metal ions,including radioactive contaminants,while maintaining the structural integrity of the MOCs.A novel MOC featuring a uranyl-sealed calix[4]resorcinarene(C[4]R)-based multisite cavity,referred to as UOC,is synthesized as a prototype.In UOC,peroxide-bridged dimeric uranyl units at both ends of the coordination cage provide abundant oxygen sites for coordination,forming a cryptand-like cavity that facilitates efficient recognition and encapsulation of Sr2+due to the size-matching effect.Additionally,hydrophobic binding cavities at both ends of UOC promote the co-inclusion of two different vip species.Inspired by the strong binding affinity of UOC for Sr^(2+),it is employed as a solid adsorbent for capturing low concentrations of Sr^(2+)in strontium-contaminated simulated groundwater.A removal efficiency of 99.7%for Sr^(2+) at an initial concentration as low as 0.013 mmol L−1 is achieved,demonstrating its significant potential for the selective removal of trace amounts of radioactive ^(90)Sr^(2+).This work demonstrates the feasibility of incorporating acyl-type metal nodes into MOCs for the recognition and encapsulation of metal ions,offering a novel strategy for developing new MOC-based functional materials.
基金
National Natural Science Foundation of China(22122609,22076186 and U20B2019)
NationalScienceFund for Distinguished Young Scholars(21925603).
