Synthesis And Properties’s Investigation Of Aromaticamine/Carbazole-based Conjugated Polymers

In this paper, two types of triphenylamine-fluorene and carbazole-fluorene basedalternating conjugated polymers were successfully synthesized by Suzuki couplingreaction. Meanwhile, its performance of ion recognition was systematically studied.We find that it has specific selectivity to I-, and successfully realized the turn-offmode for I-optical recognition response. Owing to the strong association betweenHg2+and I-, with the addition of Hg2+in the subsequent system, realization of thespecific and sensitive turn-on mode for Hg2+optical recognition response wasdetected. Furthermore, a cyano-substituted, triphenylamine-fluorescent basedconjugated polymer was obtained via efficient atom economy addition reaction by thestructure-modification of the acetylene-substituted triphenylamine-based polymerprecursor The corresponding detection performance of this polymer for I-and Hg2+has been obviously improveed. The main results are summarized as follows:1. Phenylethynyl-substituted, triphenylamine-fluorene-based alternatingconjugated polymer (P1) was successfully synthesized. The thermal andoptical properties of P1were tested. Its response of ions was investigated and theresults display that its fluorescence was efficiently quenched by the introduction of I-. Specificity for the detection of I-of P1was verified by anti-interference experimentstoward other common anionic ions, and the detection limit reaches~2.9×10-7M.Meanwhile, fluorescence of P1/I-complex recovered quickly with the presence ofHg2+. Most of background cationic ions brought slight interference to the detection ofHg2+. Detection limit of~2.4×10-7M for Hg2+can be obtained by fluorescencetitration experiment.2. A kind of triisopropylsilyl ethynyl-pendent-substituted,triphenylamine-fluorene-based conjugated polymers (P2) was synthesized in thissection and deprotected to afford acetylene-pendent substituted polymer (P3). Thecyano-substituted conjugated polymer (P4) was synthesized with high yield viaatom-economic click postfunctionalization between P3and tetracyanoethylene(TCNE) without using any catalyst. The introduction of cyano into this polymer obviously modified its detection properties for I-and Hg2+. The detection limit to I-and Hg2+can reach~9.7×10-8M and~6.9×10-9M, respectively.3In order to investigate the detection performance-chemical structurerelationship of carbazole-based optical probe, a type of2,7-carbazole and fluorenebased alternating blue-light emission conjugated polymer (P5) was synthesized bySuzuki coupling reaction. The response properties of P5to I-and P5/I-probe forHg2+were systematically investigated. Results show that P5to I-and P5/I-to Hg2+display specific selectivity, high sensitivity and excellent anti-interference, and thedetection limit to I-and Hg2+can reach~9.0×10-8M and~1.6×10-8M, respectively.