Synthesis and Physical Properties of Polyfluorene Derivative with Imidazolium Units

• Published in: Molecular Crystals and Liquid Crystals 2010-01, Vol.520 (1), p.1/[277]-9/[285]
• Main Authors: Heo, Hyo Jung, Nagamura, Toshihiko
• Format: Article
• Language: English
• Subjects: Cations; Chains (polymeric); Chemical synthesis; Derivatives; Fluorescence; Freezing; Frozen; Ionic polyfluorene derivative; P-i-n junctions; Photovoltaic cells; Physical properties; polymer frozen p-i-n junction; polymer light-emitting electrochemical cell; Polymers; thermal properties; ultrafast dynamics
• ISSN: 1542-1406; 1563-5287; 1527-1943
• DOI: 10.1080/15421401003604229

A new polyfluorene derivative (PF-ImBr) with imidazole cations as side chains was synthesized to achieve a bidirectional photo-electro conversion by single-component polymer light-emitting electrochemical cell and photovoltaic cell with frozen p-i-n junction at room temperature. Various physical properties of this polymer such as UV-vis absorption and fluorescence spectra, transient absorption, fluorescence lifetime, and thermograms were studied. The optical band gap value of PF-ImBr was estimated as 2.9 eV. The transient absorption spectra and fluorescence lifetime results strongly suggested no electronic interactions between fluorene chromophores in the main chain and imidazolium cations in the side chain. PF-ImBr film with a fluorescent chromophore and two cations in the repeating units can form a single component frozen p-i-n junction after being heated above 130°C.