The Synthesis And Photophysical Properties Of Several Luminescent Materials

Organic and polymer electroluminescence materials have attracted much interest because of its high luminescence efficiency, full color, processable and so on. In the field, many chemists are interesting in the synthesis and photophysical process of new ectroluminescent materials.Based on the analysis and summary of related literature, three organic and polymer electroluminescence (EL) materials have been synthesized. One copolymer consists of polyvinylcarbazole moiety, which can form high quality thin films with excellent hole-transporting function and binaphthyl moiety, which emits blue fluorescence. The other conjugation polymer was formed by copolymerization of N-( a -naphthyl)carbazole with l,4-di(chloromethyl)benzene. The third organic molecule was synthesized by Heck reaction with 9,9-di[(4-iodine)phenyl]fluorene and vinylcarbazole. In addition, two series of organic molecules have also been synthesized, one series is imidazole derivatives, which are formed by benzoimidazole and a-naphthyl, B-naphthyl, a-pyridyl. The other series is p-N,N-dimethlaminobenzates ((CH3)2NC6COOR, R=n-CnH2n+1, n=1,2,...8).Based on the synthesized organic compounds, the paper has emphasis on the studies of their photophysical properties. The fluorescence of the copolymer (DMBN-VCZ) spectra show that the fluorescence spectra are in good agreement with that of DMBN monomer when the solution of copolymer (DMBN-VCZ) is located in low concentration range (<10-3mg/ml). The fluorescence of copolymer (DMBN-VCZ) can be quenched by both electron donor (N,N-dimethylaniline (DMA)) .electron acceptor (1,4-dicyanobenzene (1,4-DCB)) and C60. The dimolecular exciplexes between copolymer (DMBN-VCZ) and stronger electron donor or electron acceptor are formed, respectively. Moreover, the triple exciplex was fromed between the copolymer and the DMA. The fluorescence spectra of the conjugationed polymer containing of N-( a -naphthyl)carbazole show that the emission sprctra in aromatic solvents are more red-shifted than that in aliphatic solvents although these solvents have the same polarity. The fluorescence chatacteristics were different from the N-( a -naphthyl)carbazole's. The fluorescence of the conjugationed polymer can be quenched by electron donors and CM and cannot be quenched by electron acceptors. The fluorescence spectra of imidazole derivatives show that the exciplexes were formed between them and acetic acid, respectively. Moreover the twist intramolecular charge transfer (TICT) state was appeared in (a-pyridyl) benzoimidazole. p-N,N-dimethlaminobenzates ((CH3)2NC6H4COOR) have typical ICT characteristics. The CT emission and the fluorescence intensity ratio of CT band to normal band (ICT/ILE) were different in organic solvent and in the aqueous solvent with CTAB micelle when the length of R group was increasing.The experiment results show that these compounds with superior performance were expected to apply for EL devices.