Bis(1,3-dithiolium) salt 1 containing a 1,3-di(2-thienyl)azulene unit has been designed as a novel dye. The compound 1 was synthesized by hydride abstraction of the corresponding precursor which was prepared by acid-catalyzed condensation of 1,3-bis(5-formyl-2-thienyl)azulene and 1,2-benzenedithiol. The dication 1 shows bluish green color in the acetonitrile solution and has an intense absorption at 689 nm.

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Recently, organic field-effect transistors(OFETs) using organic semiconductors have attracted much attention because of their potential applications to light, low cost and flexible devices. For achievement of high performance in OFETs, the development of new organic semiconductors with high carrier mobilities has been actively pursued. In this research, we paid attention to thiazolothiazole ring as the core ring, and aimed to develop high performance organic semiconductor by varying groups at the ends. The thiazolothiazole co-oligomers have the following advantages for the improvement of FET characteristics. First, the derivatives are easily prepared by the one-step reaction of the corresponding aldehydes with dithiooxamide. Second, the ring has a rigid planar structure due to the fused ring system like acenes. This would lead to efficient intermolecular - interactions. Third, thiazolothiazole is considered to be useful to enhance the stability to oxygen.

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Iridium complexes are expected to be highly phosphorescent materials for organic EL devices because of being used both singlet and triplet excited states. Among then, iridium complexes having phenylpyridine ligands have been extensively investigated, and emission color tuning has been achieved by introduction of substituents. However, iridium complexes having vinylpyridine ligands have not been fully explored, although these would be candidates for new blue or highly phosphorescent materials. In this report, we prepared new iridium complexes based on vinylpyridine ligands having various substituents, and measured optical properties.

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Transiiton metal complexes with 2,2'-biimidazolate monoanion (Hbim^-) ligands can form the hydrogen-bonding superstructures of a 0-D dimmer structure to a 3-D helical structure dependeing upon the number of Hbim^- ligands and the coordination structures. In this study, the novel complex, [{Ru(Hbim)₂}₂(bpm)] (bpm = 2,2'-bipyrimidine) with "a double chirality" containing two sites of the optical isomers of the delta and lamda types is prepared in order to fabrication of the 3-D chiral nano-porous crystal. Therefore, we have first performed the optical resolution of a mono nuclear complex, [Ru(Hbim)₂(bpm)], and isolated the delta and lamda optical isomer of it.

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We have synthesized a high-conductive coordination polymer, {[Ag(TANC)]}_n (5 S/cm), constructed from Ag ions and TANC (5,6,11,12-tetraazanaphthacene) radicals. The isostructural Cu coordination polymer {[Cu(TANC)]}_n, which is previously reported, also has a high-conductivity (50 S/cm) complex but the existence of the charge transfer interaction from HOMO of a Cu⁺ ion to LUMO of TANC cannot be verified. In this study, the use of the [Ag(TANC)] complex would lead to reveal the existence of the charge transfer interaction for the {[Cu(TANC)]}_n, become of no charge transfer interaction between a Ag ion and TANC.

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It is suggested that photochromic phenomena are affected by the surroundings of photosensitive dyes in the solid state. The reaction room in the solid state can be controlled by the use of inclusion compounds. For a better understanding of solid-state photochromism of organic molecules, we prepared photosensitive MCM-41 inclusion materials with N-salicylideneanilines and spiropyranes and then we measured photo-properties of them. The MCM-41 used in this study has large pores of about 4 nm in diameter. The spiropyranes in MCM-41 exhibited photo-induced reversible color change. Although photo-colored species derived from the N-salicylideneanilines in MCM-41 did not fade thermally, any photo-induced decomposition product could not be detected by NMR measurement for the photo-colored materials. Thus, the photocolored species of N-salicylideneanilines were suggested to be stabilized in the MCM-41 pores.

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Tris(tetrathiafulvaleno)dodecadehydro[18]annulene can be expected to show various functionalities such as self-assembly and multi-redox behavior. In addition, its cation radical salts may show electric conductivities. Although we already synthesized TTF-[18]annulenes having electron-withdrawing groups, donor properties of TTF units in these annulenes are decreased. Therefore, we have synthesized a novel TTF-[18]annulene containing alkylthio substituents. The synthesized annulene showed an enhanced donor ability with a self-assembling nature. The annulene also exhibited a solvato/thermo-chromism in solution and self-assembled into microscopic fibers. Novel properties such as magnetic alignment of fibers and its application to conducting devices will be discussed in detail.

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