Synthesis of NIR‐II Fluorophores by a C(sp <sup>2</sup> )−C(sp <sup>2</sup> /sp) Coupling Reaction Driven by Charge‐Transfer Interaction
Here, we report a C(sp<sup>2</sup>)-C(sp<sup>2</sup>/sp) coupling reaction driven by charge transfer interaction. Due to the strong intermolecular noncovalent interaction, an essential electron donor-acceptor (EDA) complex is formed, confirmed solidly by absorption spectra, <sup>1</sup>H NMR and single crystal X-ray diffraction. The EDA complex lowers the activation barrier (E<sub>a</sub>=9.17 kcal/mol) and facilitates the formation of the C-C bond, which is the rate-limiting step revealed by H/D and <sup>12</sup>C/<sup>13</sup>C KIE studies. Kinetic investigations reveal that the reaction is a second-order reaction. Furthermore, high-level theoretical calculations support the proposed mechanism. The mono- and di-substituted products were obtained by varying the reaction conditions. A series of structurally diverse and novel second near-infrared (NIR-II) fluorophores based on benzo[1,2-c : 4,5-c']bis([1,2,5]thiadiazole) (BBTD) were synthesized by utilizing this coupling reaction.
Authors
- Ling‐Ya Peng (ORCID: https://orcid.org/0000-0002-0589-3253)
- Ganglong Cui (ORCID: https://orcid.org/0000-0002-9752-1659)
- Li‐Ya Niu (ORCID: https://orcid.org/0000-0002-5376-6902)
- Xinxin Liu (ORCID: https://orcid.org/0000-0003-3722-9020)
- Jie Li (ORCID: https://orcid.org/0000-0002-3425-1604)
- Wenguang Wang (ORCID: https://orcid.org/0000-0002-4108-7865)
Institutions
- Beijing Normal University (CN)
Publication Details
- Journal
- Angewandte Chemie International Edition
- Published
- 2025-02-12
- DOI
- https://doi.org/10.1002/anie.202501566
- Primary Topic
- Luminescence and Fluorescent Materials
- Type
- article
- Field-Weighted Citation Impact
- 0.00