A Switchable Near‐Infrared‐Absorbing Dye Based on Redox‐Bistable Benzitetraazaporphyrin
A Switchable Near‐Infrared‐Absorbing Dye Based on Redox‐Bistable Benzitetraazaporphyrin
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基于氧化还原双稳态苯并四氮杂卟啉的可切换近红外吸收染料
DOI：
10.1002/anie.202218358
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Uchiyama Masanobu
中科院分区：
文献类型：
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作者：
Yanagi Shunsuke;Matsumoto Akihisa;Toriumi Naoyuki;Tanaka Yusuke;Miyamoto Kazunori;Muranaka Atsuya;Uchiyama Masanobu
可激活的近红外（NIR）染料对外界刺激有反应，用于医疗和其他应用。在这里，我们设计和合成了具有氧化还原可切换近红外性质的18π‐和20π‐电子苯并杂氮卟啉（BzTAPs）。X射线、核磁共振和紫外/可见近红外分析表明，20π -电子bztap1具有近红外吸收和反芳香性，具有顺性环电流，而18π -电子bztap2具有弱芳香性，具有近红外惰性。值得注意的是，在胺等温和还原剂的存在下，沉默近红外的bztap2很容易转化为具有近红外活性的bztap1。bztap1的强近红外吸收带与先前报道的抗芳香族卟啉类化合物的弱吸收带形成鲜明对比。分子轨道分析表明，20π电子类卟啉骨架的对称性降低扰动使HOMO-LUMO跃迁成为电偶极子允许的。bztap有望用于构建在还原环境中工作的可激活近红外探针。
Activatable near‐infrared (NIR) dyes responsive to external stimuli are used in medical and other applications. Here, we describe the design and synthesis of bench‐stable 18π‐ and 20π‐electron benzitetraazaporphyrins (BzTAPs) possessing redox‐switchable NIR properties. X‐Ray, NMR, and UV/Visible‐NIR analyses revealed that 20π‐electron BzTAP1exhibits NIR absorption and antiaromaticity with a paratropic ring‐current, while 18π‐electron BzTAP2shows weakly aromatic character with NIR inertness. Notably, the NIR‐silent BzTAP2was readily converted to the NIR‐active BzTAP1in the presence of mild reducing agents such as amine. The intense NIR absorption band of BzTAP1is in sharp contrast to the very weak absorption bands of previously reported antiaromatic porphyrinoids. Molecular orbital analysis revealed that symmetry‐lowering perturbation of the 20π‐electron porphyrinoid skeleton enables the HOMO–LUMO transition of1to be electric‐dipole‐allowed. BzTAPs are expected to be useful for constructing activatable NIR probes working in reductive environments.