Exotic Supramolecular Polymers

Abstract

Supramolecular polymers (SPs) represent a non-covalent alternative to traditional covalent polymers, involving the linkage of small molecular monomers through directional and reversible non-covalent interactions such as H-bonding and metal-ligand interactions.1 This presentation delves into the light-induced dynamic control of SP foldability, drawing inspiration from protein foldability-unfolding and light-induced ring opening supramolecular polymerization.2 The thoughtful design of monomers plays a crucial role in promoting efficient supramolecular polymerization by strengthening noncovalent interactions between monomer molecules. Our investigation highlights the significance of the ferrocene unit, with its restricted rotational flexibility, as an excellent facilitator for achieving the ideal conformation necessary for effective intermolecular interactions in 1,1-disubstituted ferrocenes containing non-covalent functionalities. This enhances the likelihood of successful supramolecular polymerization.3,4 Additionally, recent advancements in unique SPs showcase their ability to undergo heating-induced aqueous phase transitions, forming a hydrogel and a hydrophobic collapse-induced precipitation.5 This behavior demonstrates a lower critical solution temperature and contrasts with common supramolecular assemblies that disassemble upon heating. These aqueous SPs exhibiting phase transitions can serve as intelligent supramolecular materials with diverse applications in materials science, nanotechnology, biotechnology, and healthcare.