Dynamic Stereochemistry of M₈Pd₆ Supramolecular Cages Based on Metal‐Center Lability for Differential Chiral Induction, Resolution, and Recognition

Abstract

A series of isostructural supramolecular cages in rhombic dodecahedron shape have been assembled with distinct metal‐coordination lability (M8Pd6‐MOC‐16, M = Ru2+, Fe2+, Ni2+, Zn2+). The chirality transfer between metal‐centers generally imposes homochirality on individual cages to lead to solvent‐dependent spontaneous resolution of Δ8/Λ8‐M8Pd6 enantiomers; however, their distinguishable stereochemical dynamics manifests differential chiral phenomena governed by the cage stability following the order of Ru8Pd6 > Ni8Pd6 > Fe8Pd6 > Zn8Pd6. The highly labile Zn‐centers endow Zn8Pd6 cage with conformational flexibility and deformation, enabling intrigue chiral‐Δ8/Λ8‐Zn8Pd6 to meso‐Δ4Λ4‐Zn8Pd6 transition induced by anions. The cage stabilization effect differs from inert Ru2+ to metastable Fe2+/Ni2+ and labile Zn2+, resulting in different chiral‐guest induction. Strikingly, solvent‐mediated host‐guest interactions have been revealed for Δ8/Λ8‐(Ru/Ni/Fe)8Pd6 cages to discriminate the chiral recognition of the guests with opposite chirality. These results demonstrate a versatile protocol to control the stereochemistry of MOCs based on the dynamic metal‐centers, providing a guidance to maneuver cage chirality at a supramolecular level by virtue of solvent, anion and guest to benefit practical applications.