Photo and redox dual-stimuli-directed reversible disassembly and reassembly of linear supramolecular polymer formed by orthogonal host-guest molecular recognition

Abstract

Bottom-up fabrication of functional supramolecular systems from discrete molecular building blocks is a flourishing endeavor in contemporary science and nanotechnology. Here we present the synthesis and reversible disassembly and reassembly of adual-stimuli responsive linear supramolecular polymer constructed by host-guest molecular recognition. The formation of the supramolecular polymer is driven by exceptional selective complexation property of azobenzene with β-cyclodextrin and 4,4´-bipyridinium with sulfonatocalix[4]arene, which ensures the polymer’s controlled and orthogonal responsiveness to light irradiation and redox process. The supramolecular polymerization was confirmed by 1H NMR spectroscopy, dynamic light scattering (DLS) measurement, atomic force microscopy (AFM), and transmission electron microscopy (TEM), and its reversible photo and redox dual-responsive disassembly and reassembly behavior was as certained by UV–vis absorption spectra, cyclic voltammetry (CV), and TEM. This is the first example of a supramolecular polymer capable of reversible disassembly and reassembly driven by light and redox process, involving solely non-covalent orthogonal molecular recognition, which can be recognized by naked eyes.