Non-uniform Self-folding of Helical Poly(fluorenevinylene) Derivatives in the Solid State Leading to Amplified Circular Dichroism and Circularly Polarized Light Emission

Pengfei Wu; Adriana Pietropaolo; Mariagrazia Fortino; Shuhei Shimoda; Katsuhiro Maeda; Tatsuya Nishimura; Masayoshi Bando; Naofumi Naga; Tamaki Nakano

doi:10.1002/anie.202210556

Non-uniform Self-folding of Helical Poly(fluorenevinylene) Derivatives in the Solid State Leading to Amplified Circular Dichroism and Circularly Polarized Light Emission

Angew Chem Int Ed Engl. 2022 Oct 24;61(43):e202210556. doi: 10.1002/anie.202210556. Epub 2022 Sep 27.

Authors

Pengfei Wu^{1

2}, Adriana Pietropaolo³, Mariagrazia Fortino³, Shuhei Shimoda¹, Katsuhiro Maeda⁴, Tatsuya Nishimura⁴, Masayoshi Bando^{1

2}, Naofumi Naga⁵, Tamaki Nakano^{1

2

6}

Affiliations

¹ Institute for Catalysis (ICAT), Hokkaido University, N21W10, Kita-ku, Sapporo, 001-0021, Japan.
² Graduate School of Chemical Sciences and Engineering, Hokkaido University, N21W10, Kita-ku, Sapporo, 001-0021, Japan.
³ Dipartimento di Scienze della Salute, Università di Catanzaro, Catanzaro, Italy.
⁴ Graduate School of Natural Science and Technology and WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University Kakuma-machi, Kanazawa, 920-1192, Japan.
⁵ Department of Applied Chemistry, College of Engineering and Graduate School of Engineering and Science, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo, 135-8548, Japan.
⁶ Integrated Research Consortium on Chemical Sciences (IRCCS), Institute for Catalysis, Hokkaido University, N21W10, Kita-ku, Sapporo, 001-0021, Japan.

PMID: 35959846
DOI: 10.1002/anie.202210556

Abstract

An unprecedented non-uniform self-folding of artificial polymer chains composed of turn moieties and stretched segments is presented through the design of a set of optically active poly(fluorene-2,7-diylethene-1,2-diyl) (poly(fluorenevinylene)) derivatives bearing a neomenthyl group and a pentyl group attached at the 9-position of fluorene backbone at various ratios. The folded structure is formed and stabilized through inter-chain interactions in the solid state, leading to remarkably enhanced chiroptical properties (chirality amplification) in terms of circular dichroism (CD) and circularly polarized light (CPL) emission. This phenomenon is rationalized by experimental and theoretical CD and CPL spectral analyses. The polymer arrangements in the solid state were further assessed through transmission electron microscopic observations combined with enhanced sampling molecular dynamics simulations in the solid state revealing the thin film organizations.

Keywords: Chirality Amplification; Chirality Transfer; Circularly Polarized Light; Helix; Self-Folding.

Abstract

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