Building Fluorescent Switch Based On Naphthopyran In The Supramolecular System

Supramolecular chemistry is based on the interaction of non-covalent bonds between molecules aggregate chemical.As a new generation of macrocyclic host,pillararenes have?-rich cavities,rigid skeleton and easily being modified.Because of its unique host–guest interactions,pillararenes have found a lot of new opportunities in both self-assembly and functional applications.Naphthopyran,as an excellent photochromic material,has the advantages of sensitive reaction,high fatigue resistance and easy regulation,which has a good application prospect in the field of fluorescent switch.The purpose of this paper is to combine the two and develop a new multiply responsive fluorescent switch in the supramolecular system.The main research contents include:1.Synthesis of supramolecular polymeric host containing pillar[5]arene and pyrene fluorescent group,as well as the guest molecules containing naphthopyran photochromic group.The molecular structure of the host and guest was characterized by ¹H NMR,¹³C NMR,MS and GPC.2.The host-guest recognition properties of pillar[5]arene and naphthopyran were explored by ¹H NMR,using SEM to observe the morphological change of the host-guest self-assembly process.The recognition of host and guest was proved,and supramolecular polymeric can self-assemble into micelles in chloroform solution.3.The properties of photochromic fluorescent switches in supramolecular systems were investigated by UV absorption and fluorescence spectra.Under ultraviolet/visible light,the change of spectrum and color prove that the isomerization reaction of photochromic group can achieve the regulation of fluorescence by non-radiative energy transfer.