Boron complexes of π-extended nitroxide ligands exhibiting three-state redox processes and near-infrared-II (NIR-II) absorption properties
Boron complexes of π-extended nitroxide ligands exhibiting three-state redox processes and near-infrared-II (NIR-II) absorption properties
复制标题
π-延伸硝基氧配体的硼配合物表现出三态氧化还原过程和近红外-II (NIR-II) 吸收特性
DOI：
10.1039/d2dt02545k
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发表时间：
2022
影响因子：
4
通讯作者：
Agou Tomohiro
中科院分区：
文献类型：
--
作者：
Nakamura Marika;Hyakutake Risa;Morisako Shogo;Sasamori Takahiro;Mizuhata Yoshiyuki;Tokitoh Norihiro;Nakashima Kouichi;Fukumoto Hiroki;Agou Tomohiro
持久性自由基因其迷人的性质（包括多步氧化还原和长波长吸收特性）而引起越来越多的关注。在本研究中，通过相应的硼-氮氧配合物和二芳基胺的Buchwald-Hartwig胺化反应，合成了具有π-扩展的氮氧配体的硼配合物。这些氮氧配合物表现出两步和可逆的单电子氧化过程，这表明稳定的氧化还原三元组涉及阴离子氧化胺，中性氮氧自由基，阳离子氧代铵配体。氮氧自由基配体的阳离子硼配合物通过化学氧化的氨氧化物配合物和结构表征。阳离子氮氧自由基配合物在约1100 nm处表现出较强的吸收，表明它们作为近红外（NIR）-II活性功能染料的潜力。
Persistent radicals have attracted increasing attention owing to their fascinating properties, including multi-step redox and long-wavelength absorption characteristics. In this study, boron complexes with π-extended nitroxide ligands were synthesised via Buchwald–Hartwig amination reactions of the corresponding boron-nitroxide complex and diarylamines. These nitroxide complexes exhibited two-step and reversible one-electron oxidation processes, suggesting stable redox triads involving anionic aminoxide, neutral nitroxide-radical, and cationic oxoammonium ligands. Cationic boron complexes of the nitroxide radical ligands were obtained via chemical oxidation of the aminoxide complexes and structurally characterised. The cationic nitroxide-radical complexes exhibited strong absorptions at approximately 1100 nm, demonstrating their potential as near-infrared (NIR)-II-active functional dyes.