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Circularly Polarized Luminescence of a Stereogenic Curved Paraphenylene Anchoring a Chiral Binaphthyl in Solution and Solid State |
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| Authors: | Kenta Sato Dr Masashi Hasegawa Yuki Nojima Nobuyuki Hara Dr Tomohiko Nishiuchi Prof?Dr Yoshitane Imai Prof?Dr Yasuhiro Mazaki |
| Institution: | 1. Department of Chemistry, Graduate School of Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0373 Japan;2. Department of Applied Chemistry, Faculty of Science and Engineering, Kindai University, 3-1-4 Kowakae, Higashi-Osaka, Osaka, 577-8502 Japan;3. Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043 Japan |
| Abstract: | A curved stereogenic 6]paraphenylene (6]PP), anchoring a chiral binaphthyl scaffold at 7,7’-positions, was prepared and investigated for its properties as a solid-state circularly polarized luminescence (CPL) dye. X-ray analysis revealed a helically twisted structure of PP units induced by axial chirality of binaphthyl framework. The curved 6]PP exhibits fluorescence in powder and polymethyl methacrylate (PMMA) film as well as solution. A significant increase in quantum yield was observed for a non-fluid PMMA film owing the suppression of the molecular motion. The gCPL values of the dye in solution and as PMMA film were almost the same (4.3–4.4×10?3) and lager than that in powder. TD-DFT calculations in the excited state suggest that the exciton can be delocalized into a twisted PP unit to produce a larger magnetic transition dipole moment. |
| Keywords: | binaphthyl circular dichroism circularly polarized luminescence cycloparaphenylene PMMA film |