Synthesis and structure of an optically active π‐stacked poly(dibenzofulvene) bearing chiral terminal group |
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| Authors: | Tamaki Nakano Mitsuru Tanikawa Osamu Nakagawa Tohru Yade Takeshi Sakamoto |
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| Institution: | 1. Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060‐8628, Japan;2. Graduate School of Materials Science, Nara Institute of Science and Technology, Takayama‐cho 8916‐5, Ikoma, Nara 630‐0101, Japan |
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| Abstract: | Dibenzofulvene (DBF) affords a polymer having π‐stacked conformation by anionic, cationic, and free‐radical polymerization. In this study, DBF was polymerized anionically using potassium menthoxide as initiator to obtain optically active poly(DBF) having a chiral menthoxy group as a terminal group. The obtained polymer indicated circular dichroism (CD) absorption bands in the absorption wavelength range of fluorenyl group, indicating that chiral conformation was induced to the stacked main chain by the influence of the terminal group. The CD intensity was reversibly affected by temperature of measurement; hence, the chiral conformation may be rather dynamic. The effect of the terminal group was found to decrease as the chain length increased. Theoretical CD calculation indicated that the obtained polymer has a left‐handed helical conformation and that the dihedral angle between neighboring monomeric units might be about 10–20°. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 239–246, 2009 |
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| Keywords: | anionic polymerization calculations chiral chirality circular dichroism spectra conformational analysis helix menthol molecular modeling polydibenzofulvene synthesis |
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