Tamaki Nakano

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthetic Helical Polymers: Conformation and FunctionTamaki Nakano and Yoshio OkamotoView Author Information Graduate School of Materials Science, Nara Institute of Science and Technology (NAIST), Takayama-cho 8916-5, Ikoma, Nara 630-0101, Japan, and Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan Cite this: Chem. Rev. 2001, 101, 12, 4013–4038Publication Date (Web):Novembe

Dibenzofulvene (DBF) was polymerized using anionic initiators to afford a vinyl polymer. Oligo(DBF)s having from two to eight side-chain fluorene moieties bearing different chain-terminal groups were isolated by preparative size-exclusion chromatography. The structures of the isolated oligomers were revealed by single-crystal X-ray and (1)H NMR analyses. Both in solution and in crystal, the in-chain fluorene moieties stacked on top of each other, while the terminal conformation varied depending

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAsymmetric polymerization of triphenylmethyl methacrylate leading to a one-handed helical polymer: mechanism of polymerizationTamaki Nakano, Yoshio Okamoto, and Koichi HatadaCite this: J. Am. Chem. Soc. 1992, 114, 4, 1318–1329Publication Date (Print):February 1, 1992Publication History Published online1 May 2002Published inissue 1 February 1992https://pubs.acs.org/doi/10.1021/ja00030a030https://doi.org/10.1021/ja00030a030research-articleACS Publication

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTDibenzofulvene, a 1,1-Diphenylethylene Analogue, Gives a π-Stacked Polymer by Anionic, Free-Radical, and Cationic CatalystsTamaki Nakano, Kazuyuki Takewaki, Tohru Yade, and Yoshio OkamotoView Author Information PRESTO, Japan Science and Technology Corporation (JST) Takayama-cho 8916-5, Ikoma, Nara 630-0101, Japan Graduate School of Materials Science Nara Institute of Science and Technology (NAIST) Takayama-cho 8916-5, Ikoma, Nara 630-0101, Japan

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereospecific radical polymerization of 1-phenyldibenzosuberyl methacrylate affording a highly isotactic polymerTamaki Nakano, Masatoshi Mori, and Yoshio OkamotoCite this: Macromolecules 1993, 26, 4, 867–868Publication Date (Print):February 1, 1993Publication History Published online1 May 2002Published inissue 1 February 1993https://pubs.acs.org/doi/10.1021/ma00056a049https://doi.org/10.1021/ma00056a049research-articleACS PublicationsRequest reuse per

A preferred-handed helical conformation was induced to poly(9,9-dioctylfluoren-2,7-diyl) (PDOF) in a thin film form upon irradiation with single-handed circularly polarized light (CPL) where the induction was reversible.

Chirality induction (preferred-handed helix induction) to poly(9,9-dioctylfluorene-2,7-diyl) (poly(DOF)), poly(9,9-didodecylfluorene-2,7-diyl) (poly(DDF)), and poly(9,9-dihexylfluorene-2,7-diyl) (poly(DHF)) using circularly polarized light (CPL) was thoroughly investigated mainly using film samples. We found that the presence of the β-phase is indispensable in chirality induction to poly(DOF) which suggests the importance of interchain interactions and that chirality induction first occurs prefe

Free-radical polymerization of dibenzofulvene (DBF) was carried out under various conditions. The radical polymerization proceeded exclusively in vinyl fashion without isomerization of the growing radical or aromatic substitution by the initiator fragment. The polymerization was highly conformation-specific (stereospecific), giving a polymer with a π-stacked conformation in which the main-chain C−C bonds are nearly all trans and the side-chain fluorene moieties are stacked on top of each other.

An optically active, π-stacked poly[2,7-bis(4-tert-butylphenyl)dibenzofulvene] having a preferred-handed helical conformation was synthesized by anionic polymerization. A thin film sample of the polymer exhibited broad-band white circularly polarized light (CPL) emission on photo excitation.

Abstract Hole drift mobility of poly(dibenzofulvene) was found to be 2.7 × 10−4 cm2V−1s−1 at 299 K at a field strength of 7 × 105 Vcm−1 by the time-of-flight (TOF) measurement on a cast film containing 2,4,7-trinitrofluorenylidene-9-malononitrile as an electron acceptor. This value is higher than that of main-chain π-conjugating poly(π-phenylenevinylene) (1 × 10−5 cm2V−1s−1), is comparable to that of main-chain σ-conjugating poly(methylphenylsilane) (1 × 10−4 cm2V−1s−1), and is slightly lower th

A chirality-switching free-energy landscape was reconstructed on a 43-mer of poly(9,9-dioctylfluoren-2,7-diyl) (PDOF). The simulations were conducted on amorphous silica surface as well as in the vacuum phase for a single chain or for a group of sixteen chains. The achiral-to-chiral transition occurs only on amorphous silica (activation free-energy 35 kcal mol(-1) ), where the enantiomeric (homochiral) basins are detected. This was supported by the experiments where effective chirality induction