Liu Chang, Jin Yue, Ji Xin, Zhao Weili, Dong Xiaochun
Department of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai, 201203, P. R. China.
Key Laboratory for Special Functional Materials, of the Ministry of Education, School of Materials Science and Engineering, Henan University, Kaifeng, 475004, P. R. China.
Chemistry. 2022 Oct 7;28(56):e202201503. doi: 10.1002/chem.202201503. Epub 2022 Aug 11.
Aza-dipyrromethene boron difluoride (Aza-BODIPY) dyes have attracted much interest in recent decades. In this manuscript, we provide a facile way to access pyridine-substituted pyrroles. A series of 1/7-pyridinyl and pyridinium near-infrared (NIR) Aza-BODIPYs with/without rigidity were constructed and their spectroscopic properties were extensively investigated. These pyridinyl Aza-BOIDIPYs displayed slight bathochromic shifts and maintained bright NIR emission. Pyridinium Aza-BODIPYs showed increased bathochromic shift, however, the molar extinction coefficients and fluorescence quantum yields were decreased owing to ICT effect. The impacts followed the order of pyridin-4-ium>pyridin-2-ium>pyridin-3-ium, which was in consistence with their ICT strength. MO calculation was performed to provide possible explanation to the red-shifted absorption/emission, and apparent charge separation in pyridin-4-ium Aza-BODIPYs. The pyridinium Aza-BODIPY localized in lysosome and potentially avoided harmful ''alkalinizing effects'' of traditional lysosome-targeting fluorescent dyes containing amine moiety. We are working on construction of pyridinyl and pyridinium Aza-BODIPY photosensitizers against microbials or tumors.
近几十年来，氮杂二吡咯亚甲基二氟化硼（Aza-BODIPY）染料备受关注。在本论文中，我们提供了一种简便的方法来合成吡啶取代的吡咯。构建了一系列具有/不具有刚性的1/7-吡啶基和吡啶鎓近红外（NIR）Aza-BODIPY，并对其光谱性质进行了广泛研究。这些吡啶基Aza-BOIDIPY显示出轻微的红移，并保持明亮的近红外发射。吡啶鎓Aza-BODIPY的红移增加，然而，由于ICT效应，其摩尔消光系数和荧光量子产率降低。这种影响遵循吡啶-4-鎓>吡啶-2-鎓>吡啶-3-鎓的顺序，这与它们的ICT强度一致。进行了MO计算，以对吡啶-4-鎓Aza-BODIPY中红移的吸收/发射和明显的电荷分离提供可能的解释。吡啶鎓Aza-BODIPY定位于溶酶体中，并可能避免了含胺部分的传统溶酶体靶向荧光染料的有害“碱化效应”。我们正在致力于构建针对微生物或肿瘤的吡啶基和吡啶鎓Aza-BODIPY光敏剂。
