Luminescent Molecules Based On Tetraphenylethene And Imidazole, And Hyperbranched Polymers Based On Hydrogenated Siloles: Synthesis,Characterization, And Application

Much effort has been devoted to develop efficient solid-state emitters for their various potential applications in organic light-emitting diodes(OLEDs), organic lasers, and fluorescent probes and so on. Many conventional π-conjugated molecules suffer the aggregation-caused quenching(ACQ) effect due to the formation of detrimental species such as excimer, undermining their high-technological applications, for the fluorescent molecules are generally used as solid films or nanoparticles in the real-word applications. In 2001, Tang’s group observed an“abnormal” phenomenon, named aggregation-induced emission(AIE) effect. Some molecules with faint emission in dilute solutions can become strong emitters in the aggregated state,which is opposite to ACQ effect.In this thesis, a series of new fluorescent molecules and polymers based on tetraphenylethylene(TPE), a star molecule that possesses AIE property, and a hydrogenated silole, respectively, are synthesized and characterized. And the the potential applications are investigated.1. By connecting the 1,2,4,5-tetraphenyl-1H-imidazole(TPI) and tetraphenylethene(TPE) units together through different linking positions, a series of new TPI and TPE adducts(1, 2 and 3) were succesfully synthesized and characterized. Their optical, electronic and electroluminescence(EL) properties were fully studied. They are AIE-active because of the presence of the TPE unit.Compounds 1 and 3 show better conjugations than 2, which leads them to emit more efficiently in solid films and display better EL performances in OLEDs. It is the short conjugation of 2 that makes its EL device emit at deep-blue region(445 nm) with a CIE chromaticity coordinate of(0.16, 0.15).2. Two TPE derivatives,PIPBT-TPE and PITBT-TPE, with efficient green and red fluorescence were synthesized and utilized to prepare organic dots by encapsulation within lipid-PEG metrix. The experimental results indicate that the great potential of the present green and fluorescent organic dots in two-photonfluorescence bioimaging applications.3. A series of functional hyperbranched polymers based on hydrosilylatied silole,TDMSHS, were synthesied and characterized. They show good thermal and optical properties, and its nanoparticles in aqueous medium have be successfully applied in explosive detection.