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

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.