Stimuli-Responsive Molecular and Macromolecular Systems Controlled by Rotaxane Molecular Switches

摘要

Synthesis and dynamic nature of molecular and macromolecular systems controlled by rotaxane molecular switches are discussed. Rotaxane molecular and macromolecular switches including those working without solvent were synthesized mainly using sec-ammonium salt/crown ether couples. A linear polymer possessing a crown ether/sec-ammonium salttype [1] rotaxane moiety at the chain terminal was prepared by the rotaxane-linking of single polymer chain, and applied to the linear polymer-cyclic polymer topology transformation. Successful synthesis of macromolecular [2] rotaxane (M2R) possessing single polymer axle and one crown ether wheel made possible a variety of unique applications such as development of topology-transformable polymers and rotaxane cross-linked polymers (RCPs) by connecting polymer chains to the components of M2R. The pronounced dynamic nature of these polymer systems is quite interesting and is expected to afford much useful information for designing novel stimuli-responsive molecules, polymers, and polymer materials.