Get access

Organogels of 8-Quinolinol/Metal(II)–Chelate Derivatives That Show Electron- and Light-Emitting Properties

Authors

  • Michihiro Shirakawa Dr.,

    1. Department of Chemistry & Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan, Fax: (+81) 92-802-2820
    Search for more papers by this author
  • Norifumi Fujita Dr.,

    1. Department of Chemistry & Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan, Fax: (+81) 92-802-2820
    Search for more papers by this author
  • Takahiro Tani,

    1. Department of Chemistry & Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan, Fax: (+81) 92-802-2820
    Search for more papers by this author
  • Kenji Kaneko Prof.,

    1. HVEM Laboratory, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
    Search for more papers by this author
  • Masayoshi Ojima,

    1. Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University Suita, Osaka 565-0871, Japan
    Search for more papers by this author
  • Akihiko Fujii Prof.,

    1. Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University Suita, Osaka 565-0871, Japan
    Search for more papers by this author
  • Masanori Ozaki Prof.,

    1. Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University Suita, Osaka 565-0871, Japan
    Search for more papers by this author
  • Seiji Shinkai Prof.

    1. Department of Chemistry & Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan, Fax: (+81) 92-802-2820
    2. Center for Future Chemistry, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
    Search for more papers by this author

Abstract

8-Quinolinol/copper(II)-, palladium(II)-, and platinum(II)-chelate-based organogelators (1 M) and their nongelling reference compounds (2 M) were synthesized. Complexes 1 M could gelate various organic solvents at very low concentrations. Electron microscope measurements gave visual images of well-developed fibrous structures characteristic of low-molecular-weight organogels. UV/Vis and FTIR spectroscopy revealed that the good gelation ability of 1 M arises from the π–π interactions of the chelate moieties and the hydrogen-bond interactions among the amide groups. Very interestingly, field emission performances of the nanofibers prepared from the 1 M gels are evidently different depending on the electronic states of the three kinds of central metals. In addition, the 1 Pt gel shows unique thermo- and solvatochromism of visible and phosphorescent color in response to a sol–gel phase transition. Furthermore, the 1 Pt gel possesses an attractive ability to inhibit dioxygen quenching of excited triplet states, which increases the phosphorescence quantum yield of this gel. This effect is attributed to the isolation effect of the phosphorescent chelate moiety from the dioxygen-containing solution phase.

Ancillary