Macromolecular Rapid Communications, Vol.35, No.3, 337-343, 2014
Main-Chain Supramolecular Polymers Based on Orthogonal Benzo-21-Crown-7/Secondary Ammonium Salt and Terpyridine/Metal Ion Recognition Motifs
Orthogonal self-assembly of multiple components represents an efficient strategy to afford hierarchical and multifunctional assemblies. Here, we demonstrate the orthogonal recognition behaviors between benzo-21-crown-7/secondary ammonium salt and terpyridine/metal ions (Fe2+ or Zn2+) recognition motifs. Main-chain supramolecular polymers are subsequently achieved via one-pot mixing of the three monomers together (heteroditopic monomer 1, homoditopic secondary ammonium salt monomer 2, and Fe(BF4)(2)center dot 6H(2)O or Zn(OTf)(2)), which are confirmed by H-1 NMR, UV-Vis, DOSY, and viscosity measurements. Moreover, different metal ions (Fe2+ or Zn2+) exert considerable effects on the size of the resulting supramolecular polymers. Integration of two different types of non-covalent interactions renders dynamic and responsive properties for the resulting supramolecular polymers, as triggered by a variety of external stimuli such as temperature, potassium cation, as well as stronger chelating ligands. Therefore, the current work is a prerequisite for the future application of such orthogonal assemblies as intelligent supramolecular materials.
Keywords:host-guest interactions;metal-ligand interactions;orthogonality;stimuli-responsiveness;supramolecular polymers