Work

Guest-Programmed Adaptive Redistribution in Heteroleptic Metal–Organic Cages

Year: 2026

Type: article

Abstract: Adaptive reconfiguration of complex supramolecular assemblies remains a fundamental challenge in synthetic chemistry, especially for heteroleptic systems prone to kinetic traps and component scrambling. Here, we report a guest-coupled reassembly strategy that enables programmable redistribution between cage architectures in heteroleptic pentagonal prismatic ZnII cages, assembled via precise edge-length matching between pentatopic and tetratopic ligands. Distinct from conventional single-guest templation, these cages exhibit adaptive redistribution behavior in which multiguest recognition is coupled to host redistribution within confined cavities. Chlorinated guests are selectively encapsulated through Cl···π and π···π interactions, thereby biasing the thermodynamic landscape of assembly. Secondary guests redirect the assembly equilibrium toward distinct product distributions, including guest release, guest exchange, or stoichiometry-dependent formation of species assigned as a homoleptic pseudo-cubic cage with one or two encapsulated guests. Crystallographic, Hirshfeld surface, and computational analyses reveal that multiple Cl···π, π···π, and C–H···π noncovalent interactions within the confined cavity contribute to the selectivity of guest-directed assembly redistribution. Furthermore, the incorporation of peripheral pyrene units imparts the prismatic cages with photoluminescence, which is enhanced upon guest binding due to framework rigidification. This work demonstrates how confined multiguest recognition can be coupled to compositional redistribution within complex heteroleptic assemblies, providing a foundation for programmable adaptive supramolecular systems.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.6c04794