Balancing Ligand Flexibility versus Rigidity for the Stepwise Self‐Assembly of M12L24 via M6L12 Metal–Organic Cages. Issue 52 (17th August 2020)

• Record Type: Journal Article
• Authors: Liu, Cui‐Lian; Bobylev, Eduard O.; Fu, Yang; Poole, David A.; Robeyns, Koen; Fustin, Charles‐André; Garcia, Yann; Reek, Joost N. H.; Singleton, Michael L.
• Is Part Of: Chemistry. Volume 26:Issue 52(2020)
• Page Start: 11960
• Page End: 11965
• Publication Date: 2020-08-17
• Subjects: coordination driven self-assembly -- flexible ligands -- metal–organic cages -- structural transitions -- supramolecular chemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202001399
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Non‐covalent interactions are important for directing protein folding across multiple intermediates and can even provide access to multiple stable structures with different properties and functions. Herein, we describe an approach for mimicking this behavior in the self‐assembly of metal–organic cages. Two ligands, the bend angles of which are controlled by non‐covalent interactions and one ligand lacking the above‐mentioned interactions, were synthesized and used for self‐assembly with Pd 2+ . As these weak interactions are easily broken, the bend angles have a controlled flexibility giving access to M2 (L1 )4, M6 (L2 )12, and M12 (L2 )24 cages. By controlling the self‐assembly conditions this process can be directed in a stepwise fashion. Additionally, the multiple endohedral hydrogen‐bonding sites on the ligand were found to play a role in the binding and discrimination of neutral guests. Abstract : Two ligands, the bend angles of which are controlled by hydrogen‐bonding interactions, were used for self‐assembly with Pd 2+ . As these weak interactions are easily broken, the bend angles are flexible giving access to M2 L4, M6 L12, and M12 L24 cages. By controlling the self‐assembly conditions this process can be directed in a stepwise fashion (see scheme).