Adaptive self-assembly and induced-fit transformations of anion-binding metal-organic macrocycles.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28621312.
- Also identified by DOI 10.1038/ncomms15898 and PMC identifier 5481752.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Container-molecules are attractive to chemists due to their unique structural characteristics comparable to enzymes and receptors in nature. We report here a family of artificial self-assembled macrocyclic containers that feature induced-fit transformations in response to different anionic guests. Five metal-organic macrocycles with empirical formula of M<sub>n</sub>L<sub>2n</sub> (M=Metal; L=Ligand; n=3, 4, 5, 6, 7) are selectively obtained starting from one simple benzimidazole-based ligand and square-planar palladium(II) ions, either by direct anion-adaptive self-assembly or induced-fit transformations. Hydrogen-bonding interactions between the inner surface of the macrocycles and the anionic guests dictate the shape and size of the product. A comprehensive induced-fit transformation map across all the M<sub>n</sub>L<sub>2n</sub> species is drawn, with a representative reconstitution process from Pd<sub>7</sub>L<sub>14</sub> to Pd<sub>3</sub>L<sub>6</sub> traced in detail, revealing a gradual ring-shrinking mechanism. We envisage that these macrocyclic molecules with adjustable well-defined hydrogen-bonding pockets will find wide applications in molecular sensing or catalysis.