Construction Of TPE-based Central Porous Material And Study Of Fluorescence Sensing And Adsorption Properties

Aggregation-induced emissions(AIE)is a peculiar luminescence phenomenon discovered by Ben-Zhong Tang’s group in 2001,in which molecules exhibit luminescence with substantially enhanced fluorescence in the aggregated state due to the constraints of intramolecular rotation,vibration or motion,and this mechanism has been well verified in many molecular systems.The star molecule among AIE molecules,tetraphenylethylene(TPE),has a twisted π-π structure and a rotatable C-C single bond,and has many tetraphenylene functionalization sites,based on which many porous luminescent materials with unique luminescence properties have been developed,and these materials show excellent luminescence properties.Due to the structural uniqueness,AIE materials show great potential for applications in chemical sensors,biological probes,organic light-emitting diodes(OLEDs)and circularly polarized luminescence(CPL).In this thesis,imidazole macrocycles and porous organic polymers with AIE properties were designed and synthesized based on tetraphenylene centers,and their properties were investigated to develop ratiometric fluorescent sensors for the detection of pyrophosphate anions by imidazole macrocycles as fluorescent sensors,and porous organic polymers for the adsorption of nitro compounds,and fluorescent test strips were developed as follows.(1)Imidazole-bridged macrocyclic compounds were synthesized from TPE derivatives,which have AIE properties and can be used as ratiometric fluorescent sensors with AIE characteristics for the specific detection of pyrophosphate anions.The imidazole macrocycles are bound to pyrophosphate ions with their suitable cavity size,and then by electrostatic interaction with zinc ions,which leads to the formation of aggregates and the emission of strong fluorescence,due to the enhanced emission of their aggregates and the reduced emission of the monomer.It was demonstrated experimentally that this fluorescence luminescence enhancement does not occur for imidazole macrocycles compounds with other anions,thus enabling specific detection of pyrophosphate anions,and this AIE macrocycles show great potential as fluorescent sensors.(2)A porous organic polymer(FPOP)with strong fluorescence and tunable luminescence color was synthesized by a simple and economical coupling method,and the better stability,excellent detection and adsorption ability of the material were experimentally demonstrated.When nitroaromatic compounds are added,the luminescence of FPOP produces quenching phenomenon,and the low preparation cost and fast reaction speed of FPOP make it a potential candidate material for fluorescence detection of nitroaromatic compounds.In addition,we have developed fluorescent test strips where FPOP shows higher adsorption capacity and rate than other reported adsorbents,with the highest level of detection of nitro compounds up to 10-8 M,and rapid response time and visual detection,which could be a potential effective adsorbent for industrial use.