Building Multiple Response Fluorescent Switch Based On The Photochromic Properties Of Naphthopyran And The Host And Guest Recognition Propertiesof Pillar[n]arene

Pillar[n]arenes are a new class of macrocyclic hosts.Because of its stable partial flexible structure,easily modify terminal groups,favorable recognition and selection,wide range of applications and other characteristics.Pillar[n]arenes have attracted more attention.and it has grown rapidly.Pillar[n]arenes have significant selectivity for different ionics,micromolecules and macromolecules.So there are constantly used to control enhancement and attenuation of fluorescence by the favorable recognition and selection.Naphthopyrans is an excellent photochromic material with good fatigue resistance,rapidly photoresponsiven and large color gamut ranges.The opened naphthopyran can quenched the emission of fluorophore via the energy transfer from fluorophore to opened naphthopyran Therefore,naphthopyran is constantly used in the photochromic fluorescent switch.In this dissertation,a supramolecular polymer system including supramolecular host-guest recognition and competition,the photochromism of naphthopyran and fluorescence switching were constructed.Multiply modulation of fluorescence was achieved through the host-guest recognition and photochromic properties of naphthopyran,so the multiply responsive fluorescent switch is fabricated.The main content as following:1.The supramolecular polymeric host containing naphthopyran and pillar[5]arene of is synthesized.And the pyrene-containing fluorescent guest is synthesized.2.The structure of the host and guest was characterized by 1H NMR,13 C NMR,IR,MS and GPC.3.The recognition properties of host and guest(pillar[5]arene and fluorescent guest)were investigated by 1H NMR.4.Upon the irradiation of ultraviolet light,the change of the absorbance and the fluorescence spectra and the color changes of the solution and the film demonstrated that the fluorescence was modulated by the photochromic naphthopyran.After the addition of different guest molecules,the fluorescence disappearing of the supramolecular system show that the fluorescence is controlled by the competitive recognition of host and guest.