Metal‐Bridging Cyclic Bilatriene Analogue Affords Stable π‐Radicaloid Dyes with Near‐Infrared II Absorption
Stable neutral metal radicaloid complexes have been synthesized from a modified tetrapyrrolic pigment, bilatriene, with iridium(I) and rhodium(I) cyclooctadiene (COD) synthons. The bilatriene skeleton contains α-linked conjugated pyrrole units, whereas an N-confused analogue used in this work possesses β-linked pyrrole moieties at the terminal, demonstrating a unique metal binding capability. Unprecedentedly, the metal-COD cations are accommodated at the outer nitrogen sites, which induced the formation of open-shell metal-radicaloid species. The resulting compounds are highly stable under ambient conditions and demonstrated facile redox conversion to afford the corresponding cation and anion species. Furthermore, the radicaloid complexes showed a distinct second near-infrared absorption (NIR-II) capability extending up to 1500 nm along with high photostability. These features emphasized that the complexes can be potential NIR-II light-responsible photothermal and photoacoustic imaging contrast agents based on the metal-radicaloid dye platform.
Authors
- Shigeki Mori (ORCID: https://orcid.org/0000-0001-6731-2357)
- Yuki Ide (ORCID: https://orcid.org/0000-0003-0648-0503)
- Jun Tae Song (ORCID: https://orcid.org/0000-0003-1047-6152)
- Hiroyuki Furuta (ORCID: https://orcid.org/0000-0002-3881-8807)
- Tatsumi Ishihara (ORCID: https://orcid.org/0000-0002-7434-3773)
- Anupam Ghosh (ORCID: https://orcid.org/0000-0001-9865-6945)
- Yoshihisa Yamaoka (ORCID: https://orcid.org/0000-0001-6395-7721)
- Masatoshi Ishida (ORCID: https://orcid.org/0000-0002-1117-2188)
- Takahisa Ikeue (ORCID: https://orcid.org/0000-0002-1673-1532)
Institutions
- Kyushu University (JP)
- Shimane University (JP)
- Hokkaido University (JP)
- Komatsu University (JP)
- Matsuyama University (JP)
- Rigaku (Japan) (JP)
- Kyushu International University (JP)
- Ehime University (JP)
- Tokyo Metropolitan University (JP)
Publication Details
- Journal
- Angewandte Chemie International Edition
- Published
- 2024-12-10
- DOI
- https://doi.org/10.1002/anie.202418751
- Citations
- 6
- Primary Topic
- Luminescence and Fluorescent Materials
- Type
- article
- Field-Weighted Citation Impact
- 0.70
Funders
- Japan Society for the Promotion of Science London
- Ministry of Education, Culture, Sports, Science and Technology
- Izumi Science and Technology Foundation
- Japan Society for the Promotion of Science
- Japan Science and Technology Agency
- Precursory Research for Embryonic Science and Technology