Dinuclear Triple-Stranded Helicates Composed of Tetradentate Ligands with Aluminum(III) Chromophores: Optical Resolution and Multi-color Circularly Polarized Luminescence Properties

Toshikazu Ono; Kohei Ishihama; Ai Taema; Takunori Harada; Kiyonao Furusho; Masashi Hasegawa; Yuki Nojima; Masaaki Abe; Yoshio Hisaeda

doi:10.1002/anie.202011450

Dinuclear Triple-Stranded Helicates Composed of Tetradentate Ligands with Aluminum(III) Chromophores: Optical Resolution and Multi-color Circularly Polarized Luminescence Properties

Angew Chem Int Ed Engl. 2021 Feb 1;60(5):2614-2618. doi: 10.1002/anie.202011450. Epub 2020 Dec 1.

Authors

Toshikazu Ono¹, Kohei Ishihama¹, Ai Taema¹, Takunori Harada², Kiyonao Furusho², Masashi Hasegawa³, Yuki Nojima³, Masaaki Abe⁴, Yoshio Hisaeda¹

Affiliations

¹ Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu Univerisy, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
² Department of Integrated Science and Technology, Faculty of Science and Technology, Oita University, Dannoharu 700, Oita City, 870-1192, Japan.
³ Department of Chemistry, Graduate School of Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan.
⁴ Department of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Hyogo, 678-1297, Japan.

PMID: 33064346
DOI: 10.1002/anie.202011450

Abstract

New chiroptical chromophores, dinuclear triple-stranded helicates, composed of tetradentate ligands with aluminum(III) ions, are described. These are synthesized in two steps using inexpensive pyrrole derivatives, hydrazine, and aluminum chloride. These molecular architectures (ALPHY) show multi-color (cyan, yellow, and orange) photoluminescence in solution and in the solid-state, which depends on the substituents of the ligands. The photoluminescence quantum yields of helicates were up to 54 %. The right-handed (P) and left-handed (M) helicates are so stable that they do not undergo racemization in some solvents and are mirror images according to circular dichroism and circularly polarized luminescence (CPL) with an absolute luminescence dissymmetry factor (g_lum ) of up to the 10^-3 order. Mixing the different helicates produces white-light emission with CPL characters. This study offers a glimpse into the potential applications of chromophores with diverse photophysical properties.

Keywords: aluminum complexes; circularly polarized luminescence; helical structures; optical resolution; white-light emission.

Abstract

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