Supramolecular Structures and Nanoassemblies of Tetrathiafulvalene Oligomers

Self-assembly and nanostructure formation of tetrathiafulvalene (TTF) oligomers using S and π-π interactions are summarized. Thus, tris(TTF)-annulenes were prepared by palladium-catalyzed couplings of diethynyl-TTFs. Multi-functional TTF-annulenes show various chromic properties in solution and the nanofiber formation in the solid state. Interestingly, the diamagnetic responsibility of the [18]annulene can be employed for the fiber alignment in a magnetic field. Fur-thermore, flexible star-shaped TTF oligomers were prepared by Sonogashira coupling of iodo-TTF with ethynylbenzenes. The star-shaped TTFs show strong self-aggregation in solution. In the case of the star-shaped hexamer, hexagonally ordered one-dimensional nanofibers are constructed both in neutral and cationic states. The electric conductivity of the cation-radical fiber is 2 orders of magnitude higher than that of the cation-radical film.