Spontaneous Resolution of Chiral Janus-Type Double-Layered Metallocyclic Strips Incorporating Mo''bius Ring and Circular Helicate

Homochiral metal-organic macrocyclic complexesare of greatsignificance owing to their chirality and well-defined internal cavitiesthat potentially have the ability to mimic complicated biologicalprocesses. Here we report a novel metal/anion-coordination co-drivenstrategy for the formation of nanoscale supramolecular metallocycleswith unique topology, large size, and desired chirality. The enantiomericJanus-type metallocyclic strips are assembled based on the synergisticcoordination of sulfate anions and Co-II ions to a bifunctionalachiral ligand combining the o-phenylene-(bis)ureaanion-chelating and 8-hydroxyquinoline metal-coordinating sites. Theinherent chirality arises from two types of helical chiralities (triplytwisted Mo''bius ring and circular helicate), which is observedfor the first time for metal-organic complex systems. Notably,spontaneous chiral resolution by conglomerate crystallization intoa pair of enantiomers ( P- or M- Co ( 9 ))is realized, which is attributed to the multiple weak intermolecular interactions facilitating the hierarchically helical superstructure.

Automated summary

This study presents a novel metal/anion-coordination co-driven strategy for the synthesis of nanoscale supramolecular metallocycles with unique topology and desired chirality. The enantiomeric Janus-type metallocyclic strips are formed through the synergistic coordination of sulfate anions and Co-II ions to a bifunctional chiral ligand. The chirality is derived from two types of helical chiralities, namely triply twisted Mo''bius ring and circular helicate, which represent a new phenomenon in metal-organic complex systems.