title: Facile Two-Step Synthesis of 1,10-Phenanthroline-Derived Polyaza[7]helicenes with High Fluorescence and CPL Efficiency.
abstract: A facile two-step synthesis of aza[7]helicenes possessing a 6-5-6-6-6-5-6 skeleton from commercially available 2,9-dichloro-1,10-phenanthroline via double amination with aniline derivatives followed by hypervalent iodine reagent-mediated intramolecular double-NH/CH couplings was developed. Single-crystal X-ray analyses of the helicenes revealed unique structures, including both a significantly twisted center and planar terminals of the skeleton. The azahelicenes show high fluorescent quantum yields (Φs) under both neutral (Φ: 0.25-0.55) and acidic conditions (Φ: up to 0.80). An enantiomerically pure aza[7]helicene showed high circularly polarized luminescence (CPL) activity under both neutral and acidic conditions (glum: up to 0.009).
authors.affiliation: Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo, 169-8555, Japan.|Course of Chemical Engineering, National Institute of Technology Anan College, 265 Aoki, Minobayashi, Anan, Tokushima, 774-0017, Japan.|Research Institute for Science and Technology, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, T, okyo, 162-8601, Japan.|JST, ACT-C, 4-1-8 Honcho, Kawaguchi, Saitama 3, 32-0012, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Otani
authors.affiliation: Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo, 169-8555, Japan.
authors.forename: Ami
authors.initials: A
authors.lastname: Tsuyuki
authors.affiliation: Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Iwachi
authors.affiliation: Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo, 169-8555, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Someya
authors.affiliation: Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Tateno
authors.affiliation: Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kawai
authors.affiliation: Research Institute for Science and Technology, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, T, okyo, 162-8601, Japan.|Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Saito
authors.affiliation: International Center for Science and Engineering Programs (ICSEP), Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo, 169-8555, Japan.
authors.forename: Kyalo Stephen
authors.initials: KS
authors.lastname: Kanyiva
authors.affiliation: Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo, 169-8555, Japan.|JST, ACT-C, 4-1-8 Honcho, Kawaguchi, Saitama 3, 32-0012, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Shibata
keywords: X-ray diffraction; azahelicene; circularly polarized luminescence; fluorescence; oxidative coupling