Novel copolymers containing the indolo [3,2-b]carbazole (INC) moiety were synthesized, and the effects of the INC content on their physical properties were investigated. The homopolymer of the INC-containing monomer, 1-octyl-7-(4-vinylbenzyl) indolo [3,2-b]carbazole and copolymers with styrene were prepared by radical polymerization. Four kinds of copolymers with different compositions were obtained. The glass transition temperatures (Tgs) were observed in the range of 101-112 1C, and the decomposition temperatures were nearly 400 1C. The photonic properties of the copolymers were also evaluated in solution in tetrahydrofuran and for spin-coated films on a fused silica substrate. In the ultraviolet-visible absorption spectra, maximum absorption peaks were observed at 340-345 nm in both the solutions and the films. In the case of the solutions, the photoluminescence intensities of the copolymers increased with increasing INC monomer units in the copolymer. On the contrary, the photoluminescence intensities of the copolymer films decreased with increasing INC content in the copolymer, which is likely due to the concentration quenching caused by the condensation of intermolecular interactions derived from INC components. The copolymer with a low content of the INC moiety exhibited high emission and good film-forming ability.

In this study, the syntheses of indolo[3,2-b]carbazole (INC) derivatives have been investigated, which possessed the planer and conjugated structure and showed the strong blue fluorescence by the irradiation of UV light. In order to improve the solubility of INC, N-alkylated INC derivatives were prepared by the reaction of INC with NaH followed by the addition of alkyl halides, the carbon numbers of which were C 1-C 10. The obtained alkylated INCs were soluble in some solvents, and the unique thermal properties were observed for the alkylated INCs with a long alkyl chain, which became amorphous after melting and showed the mesomorphic-like transitions. According to the fluorescence spectroscopy, these alkylated INC derivatives exhibited the strong emission, the quantum yield of which was about 0.50. On the other hand, the INC derivative containing an octyl group and a p-vinylbenzyl group at N-positions was prepared as a monomer compound to obtain polystyrenetype polymer with INC moiety by a radical polymerization. It was found that the polymer was a glassy polymer and the coating film was easily prepared. In addition, the obtained polymer exhibited a high thermal stability, which maintained the high emission property of INC moiety.

HP1

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In this study, the synthesis of an indolo [3,2-b]carbazole (INC) derivative containing an octyl group and a pvinylbenzyl group at N-positions was carried out as a monomer compound to obtain copolymers with methyl methacrylate (MMA) by a radical polymerization. These copolymers showed the amorphous state and exhibited the higher thermal stability as INC content increased, which maintained the high emission property of INC moiety. Furthermore, the spin-coating and casting films could be prepared form the copolymer solutions. Then, it was found that the strong photoluminescence was observed for these polymer films, the INC content of which was ca. 5 mol%.

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In this study, we have attempted to prepare novel aromatic polyamides containing indolo[3,2-b]carbazole (INC) moiety in the main chain. For this purpose, the synthesis of an aromatic dicarboxyl compound containing INC moiety was carried out. Novel aromatic polyamides containing INC moiety in the main chain were prepared by the polycondensation of the dicarboxyl INC monomer with the four kinds of diamine monomers. The obtained polymers were soluble in aprotic polar solvents such as N,N-dimethyl acetamide and N-methyl-2-pyrrolidone. According to the thermal gravimetric analysis, the obtained polyamides exhibited the relatively high thermal stability and the high char yield nearly 50 % at 1000 °C in the thermal degradation. Furthermore, it was found from the evaluation of the photonic property that the UV-Vis absorption and fluorescence spectra of these polyamides showed the similar tendency of the photonic property of INC.

Several composites were obtained by polycondensation reaction using metal phthalocyanine having carboxy groups and p-phenylenediamine. The obtained composites were pyrolyzed at 900 °C in a hydrogen stream to afford the cathode catalysts for polymer electrolyte fuel cells (PEFC). The catalysts were treated with aqua regia to investigate the influence of metal content on oxygen reduction activity (ORA). Comparing the ORA of the catalysts before and after the aqua regia treatment, the ones containing metal had higher activity. It became clear that the presence of metal is indispensable for improving ORA.