Tailor‐Made Pd_nL_2n Metal‐Organic Cages through Covalent Post‐Synthetic Modification

Abstract

Post‐synthetic modification (PSM) is an effective approach for the tailored functionalization of metal‐organic architectures, but its generalizability remains challenging. Herein we report a general covalent PSM strategy to functionalize PdnL2n metal‐organic cages (MOCs, n=2, 12) through an efficient Diels–Alder cycloaddition between peripheral anthracene substituents and various functional motifs bearing a maleimide group. As expected, the solubility of functionalized Pd12L24 in common solvents can be greatly improved. Interestingly, concentration‐dependent circular dichroism and aggregation‐induced emission are achieved with chiral binaphthol (BINOL)‐ and tetraphenylethylene‐modified Pd12L24, respectively. Furthermore, Pd12L24 can be introduced with two different functional groups (e.g., chiral BINOL and achiral pyrene) through a step‐by‐step PSM route to obtain chirality‐induced circularly polarized luminescence. Moreover, similar results are readily observed with a smaller Pd2L4 system.