Self-Assembled Helical Nanofibers Made of Achiral Molecular Disks Having Molecular Adapter
journal contributionposted on 26.10.2010, 00:00 by Mutsumi Kimura, Tatsuya Hatanaka, Hirotaka Nomoto, Junko Takizawa, Tadashi Fukawa, Yoko Tatewaki, Hirofusa Shirai
An achiral disk-shaped molecule (2) having one imidazole unit was found to be assembled into long and twisted nanoscopic fibers having 10 - 100 nm width as shown by transmission electron microscopy (TEM) and atomic force microscope (AFM). Compound 2 leads to spontaneous chiral symmetry breaking through the steric effect of imidazole units during the formation of one-dimensional stacks. The imidazole in 2 acts as a molecular adaptor to form hydrogen bonds and accumulate metal ions. The supramolecular connection of 2 with benzene-1,3,5-tricarboxylic acid through the hydrogen bonds exhibited a thermotropic liquid crystalline properties. Silver nanoparticles were deposited onto the self-assembled nanofibers by the photoreduction of silver ions.