Design And Synthesis Of Aggregation Induced Enhanced Emission Materials Of Cyanostilbene

Organic luminescent materials have a wide range of applications in stimuli response materials,chemical sensors,organic light-emitting diodes(OLEDs),biological fluorescent probes,liquid crystal and other fields.However,conventional organic luminescent molecules cause fluorescence quenching due to the formation of H-aggregates,exciplexes etc.in the aggregated states.Aggregation-induced enhanced emission(AIEE)materials as a new type of luminescent materials overcome the disadvantages of fluorescence concentration quenching.In this thesis,a series of cyanostilbene derivatives having AIEE properties were designed and synthesized by structure modification with cyanostilbene as the principal part on the basis of investigation of literature of domestic and foreign cyanostilbene AIEE luminescent materials.The photophysical properties,aggregation-induced emission and sensor properties were studied.The main work carried out by this thesis is as follows.1.Eight kinds of cyanostilbene organoboron compounds APABF,APABBF,APAHF,APAHBF,TPEBEPBF,TPEHBF,TPEHBBF,TPEBF,with different push-pull electron groups and AIEE properties were designed and synthesized through trifluoride diethyl ether solvent reacts with imine Schiff base,which formed by condensation of salicylaldehyde structure and aryl amine with cyanostilbene.The structures of intermediates and target products were characterized by modem analytic methods,such as FT-IR,1H-NMR and 13C-NMR.The basic photophysical properties of series compounds were studied by UV-Vis absorption spectra and fluorescence emission spectra.The research results show that the different push-pull electron groups and heavy atoms have a regulatory effect on the fluorescence wavelength of these types of organoboron compounds.An AIEE organoboron compound TPEBEPBF containing cyanostilbene group was designed and synthesized based on the resonance fluorescence energy transfer mechanism.The energy transfer process was investigated by UV-Vis absorption spectra and fluorescence emission spectra.A kind of organoboron compound TPEBF with charge chansfer property was synthesized,and its photophysical properties were investigated in detail.The research shows it has AIEE property.Furthermore,the compound can be used for selective fluorescence recognition of trinitrophenol(PA)and an acid/base switch in aggregated state.The detection limit of PA was 204 nM.The reversible acids/bases switch was realized by fluorescence intensity significantly quenched after steaming TPEBF with trifluoroacetic acid and restored after steaming with triethylamine.2.Eight kinds of imidazole compounds AHTPEAIM,HTPEAIM,ATPEAIM,AHTPEAIMB,TPATPEIM,TPETPAIM,DTPEIM,DPTPEIM,which containing structural units of cyanostilbene and tetraphenylethylene were designed and synthesized by Debus-Radziszewski,Suzuki and Knoevenagel reaction,and their structure were characterized in detail.The results showed the introduction of different push-pull electron groups had a significant impact on the fluorescence emission of the compounds.The effects of different substituents on the thermal stability of the compounds were compared.The results showed that tetraphenylethylene structural units could improve the thermal stability of the compounds.Among them,compound HTPEAIM could recognize Cu2+ by fluorescence selectively.The fluorescence of HTPEAIM in aggregated states was quenched by Cu2+,which made selective recognition towards Cu2+ in aqueous solution achieved.The limit of detection was 2.81?M.3.Two terpyridine derivatives containing cyanostilbene group,CZATPY and TPEATPY,were designed and synthesized by Suzuki and Knoevenagel reaction,and their structure were characterized.The basic photophysical properties and properties of aggregation induced emission were basically studied.The two compounds were selected to identify Fe2+ and Fe3+ in aqueous solution respectively and realized visualization.The mechanism was a metal-ligand charge transfer absorption peak.The binding ratio between CZATPY and Fe2+ was 2:1,and the detection limit was 1.63?M.The binding ratio between TPEATPY and Fe3+ was 1:1,and the detection limit was 0.81 ?M.