Bowl-Shaped Anthracene-Fused Antiaromatic Ni(II) Norcorrole: Synthesis, Structure, Assembly with C60, and Photothermal Conversion

• Published in: Angewandte Chemie International Edition 2024-11, p.e202419289
• Main Authors: Wang, Kaisheng, Ghosh, Aninda, Shimizu, Daiki, Takano, Hideaki, Ishida, Masatoshi, Kishi, Ryohei, Shinokubo, Hiroshi
• Format: Article
• Language: English
• ISSN: 1521-3773; 1521-3773
• DOI: 10.1002/anie.202419289

The synthesis of bowl-shaped antiaromatic molecules is challenging because the molecular distortion further destabilizes these already inherently reactive molecules. Here, we report the synthesis and properties of bowl-shaped fused anthrylnorcorroles that exhibit near-infrared (NIR) absorption reaching 1900 nm. The oxidation of meso-anthryldibromodipyrrin provides fused anthryldibromodipyrrin, which was converted to the fused mono- and bisanthrylnorcorroles through Ni(0)-mediated intramolecular coupling with a bis(dibromodipyrrin) Ni(II) complex. Single-crystal X-ray diffraction analyses revealed bowl-shaped structures for the fused mono- and bisanthrylnorcorroles, which enables them to act as suitable receptors for C60 with bonding constants of 2.89×103 M-1 and 1.59×103 M-1, respectively. The formation of a 1 : 1 complex between the fused monoanthrylnorcorrole and C60 was confirmed by single-crystal X-ray diffraction analysis. The effective expansion of the π-conjugation through the triple fusion of the norcorrole with the anthracene units substantially enhances the near-infrared absorption bands, which endows these anthrylnorcorroles with effective photothermal conversion.The synthesis of bowl-shaped antiaromatic molecules is challenging because the molecular distortion further destabilizes these already inherently reactive molecules. Here, we report the synthesis and properties of bowl-shaped fused anthrylnorcorroles that exhibit near-infrared (NIR) absorption reaching 1900 nm. The oxidation of meso-anthryldibromodipyrrin provides fused anthryldibromodipyrrin, which was converted to the fused mono- and bisanthrylnorcorroles through Ni(0)-mediated intramolecular coupling with a bis(dibromodipyrrin) Ni(II) complex. Single-crystal X-ray diffraction analyses revealed bowl-shaped structures for the fused mono- and bisanthrylnorcorroles, which enables them to act as suitable receptors for C60 with bonding constants of 2.89×103 M-1 and 1.59×103 M-1, respectively. The formation of a 1 : 1 complex between the fused monoanthrylnorcorrole and C60 was confirmed by single-crystal X-ray diffraction analysis. The effective expansion of the π-conjugation through the triple fusion of the norcorrole with the anthracene units substantially enhances the near-infrared absorption bands, which endows these anthrylnorcorroles with effective photothermal conversion.