Adaptive self-assembly and induced-fit transformations of anion-binding metal-organic macrocycles
نویسندگان
چکیده
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 MnL2n (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 MnL2n species is drawn, with a representative reconstitution process from Pd7L14 to Pd3L6 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.
منابع مشابه
Self-Assembled Ring-in-Ring Complexes from Metal-Ligand Coordination Macrocycles and β-Cyclodextrin
We present a simple and efficient approach to ring-inring nanostructures from readily available starting materials through self-assembly process. The self-assembly tool kit includes divalent dipyridyl ligands, Pd(II) metal ions, and β-cyclodextrin (β-CD). A series of dipyridyl ligands are shown to form inclusion complexes with β-CD in aqueous solution as a result of hydrophobic interactions. On...
متن کاملEffect of competing alkali metal cations on neutral Host's anion binding ability
Anion binding by neutral hosts in organic solvents can be inhibited by the presence of alkali metal cations. The binding inhibition is due to salt ion-pairing which increases in the order Cs(+) < K(+) < Na(+). The binding inhibition can be reversed by using heteroditopic hosts that simultaneously bind both the metal cation and the anion. The largest cation-induced enhancements are observed with...
متن کاملTorands Revisited: Metal Sequestration and Self-Assembly of Cyclo-2,9-tris-1,10-phenanthroline Hexaaza Macrocycles.
A series of novel toroidal cyclo-2,9-tris-1,10-phenanthroline macrocycles with an unusual hexaaza cavity are reported. Nickel-mediated Yamamoto aryl-aryl coupling was found to be a versatile tool for the cyclotrimerization of functionalized 1,10-phenathroline precursors. Due to the now improved processability, both liquid-crystalline behavior in the bulk phase and two-dimensional self-assembly ...
متن کاملMulti component self-assembly: supramolecular organic frameworks containing metal-rotaxane subunits (RSOFs).
A facile, one-pot synthesis of rotaxanated supramolecular organic frameworks (RSOFs) is reported. These systems consist of bis-carboxylate anions threaded through the core of tetraimidazolium macrocycles. Trivalent metal cations, yttrium(III) and smaller lanthanides, are used to "lock" the threaded strut in place. This results in the formation of three-dimensional RSOFs.
متن کاملDiversity of metal-organic macrocycles assembled from carbazole based ligands with different lengths.
A series of carbazole based ligands with different lengths were assembled with nickel ions to construct metal-organic macrocycles. High-resolution mass spectrometry and ion mobility-mass spectrometry have been used to analyse the resulting MnLn assembly coexisting in solution. Combining with the structural analysis of their solid confirmation, it was revealed that the diversity of the metal-org...
متن کامل