Publisher：Journal of Polymer Science  

A series of novel biphenylylacetylene (BPA)-based chiral/achiral copolymers bearing a small amount of configurationally labile optically active [5]helicene pendants (5, 10, and 20 mol%) introduced at the 4′-position of the biphenyl units was synthesized. An almost fully right (P)-handed helical copolymer was obtained when copolymerized with 10 mol% of the (M)-[5]helicene-bound BPA monomer, indicative of a very strong sergeants and soldiers effect. The (M)-helicene units of the copolymers are configurationally labile and gradually racemized over time. However, the copolymer with 10 mol% of the (M)-[5]helicene-bound BPA mostly maintained its preferred-handed helicity even after the pendant helicene units were completely racemized, which can be ascribed to the static memory of the main-chain helicity stabilized by the bulky yet racemic helicene units. Hence, the helicity memory of the corresponding helicene-free homopolymer was lost rapidly. For comparison, an optically inactive copolymer containing 10 mol% of the racemic [5]helicene units was also prepared, and noncovalent helicity induction and subsequent memory of the helicity as well as its helix-memory stability were investigated.

DOI： 10.1002/pol.20220658

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)  

A rigid wing-shaped bicyclo[2.2.2]octadiene-fused bis-hexapyrrolohexaazacoronene (HPHAC) is synthesized, and subsequent chemical oxidation affords a stable biradical dication and an aromatic tetracation. The physicochemical properties and single-crystal structures in various oxidation states are characterized. The face-to-face π-stacked dimeric structures are observed in the neutral and dicationic states. The HPHAC flakes can act as aromatic walls in a tetracation state, producing enlarged induced magnetic shielding space through the superimposition effect.

DOI： 10.1021/acs.orglett.1c03669

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DOI： 10.1021/acs.joc.0c03042

PubMed

Language：English  

DOI： 10.1021/jacs.9b09260

PubMed

Language：English  

DOI： 10.1021/jacs.8b06079

PubMed

Language：English   Publisher：公益社団法人 日本化学会  

<p>A cyclophane composed of diethanoanthracene (DEA)-fused dipyrrole and tetrafluorobenzene was synthesized by one-pot aromatic nucleophilic substitution (S_NAr). Reflecting the fixed angle of DEA-fused dipyrrole, X-ray single-crystal structure analysis of the cyclophane revealed its rice-ball-shaped structure.</p>

DOI： 10.1246/cl.161026

Web of Science

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