title: Stabilization of Charge Carriers in Picket-Fence Polythiophenes Using Dielectric Side Chains.
abstract: Insulated molecular wires (IMWs) are π-conjugated polymers that are molecularly sheathed with an insulating layer and are structurally analogous to electric power cords at the nanoscale. Such unique architectures are expected in molecular electronics and organic devices. Herein, we propose a new molecular design concept of IMWs, in which the sheaths can be customized, thereby enabling the modulation of the electronic properties of the interior π-conjugated systems. To this end, we focused our attention on the dielectric constant of the sheaths, as it governs the electrostatic interaction between charges. Upon doping, charge carriers, such as polaron and bipolaron, were generated regardless of the dielectric properties of the sheaths. Flash-photolysis time-resolved microwave conductivity measurements revealed that intrawire charge carrier mobility was independent of the sheaths. However, we found that the charge carriers could be stabilized by the sheaths with a high dielectric constant owing to the charge screening effect. We expect that IMWs designed in this way will be useful in a variety of applications, where the nature of charge carriers plays an important role, and particularly when redox switching is required (e.g., electrochromic, magnetic, and memory applications).
authors: Molecular Design & Function Group, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan.|Department of Materials Science and Engineering, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan.
authors: Chunhui
authors: C
authors: Zhao
authors: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.
authors: Tsuneaki
authors: T
authors: Sakurai
authors: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
authors: Satoru
authors: S
authors: Yoneda
authors: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan. seki@moleng.kyoto-u.ac.jp.
authors: Shu
authors: S
authors: Seki
authors: Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan.
authors: Manabu
authors: M
authors: Sugimoto
authors: Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata, 940-2188, Japan.
authors: Choji
authors: C
authors: Oki
authors: Molecular Design & Function Group, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan. TAKEUCHI.Masayuki@nims.go.jp.|Department of Materials Science and Engineering, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan. TAKEUCHI.Masayuki@nims.go.jp.
authors: Masayuki
authors: M
authors: Takeuchi
authors: Molecular Design & Function Group, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan. SUGIYASU.Kazunori@nims.go.jp.
authors: Kazunori
authors: http://orcid.org/0000-0001-5699-2772
authors: K
authors: Sugiyasu
keywords: charge carriers; dielectric constants; insulated molecular wires; polythiophenes