J- and H-aggregates of heavy-atom-free Aza-BODIPY dyes with high 1O2 generation efficiency and photodynamic therapy potential
J- and H-aggregates of heavy-atom-free Aza-BODIPY dyes with high 1O2 generation efficiency and photodynamic therapy potential
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DOI：
10.1016/j.dyepig.2022.110813
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发表时间：
2022-10-07
影响因子：
4.5
通讯作者：
Xing, Guo-wen
中科院分区：
文献类型：
--
作者：
Liu, Yi-chen;Zhang, Yuan;Xing, Guo-wen
分子的聚集提供了一种简便的方法来调节染料的光学性质，从而为具有光动力学治疗（PDT）潜力的有机纳米光敏剂（PS）提供了一个设计平台。然而，如何控制染料单体的分子结构以形成特定的聚集体，从而使PDT的效率最大化，仍然是一个巨大的挑战。在此，我们提出了一种新的超分子策略，以构建纳米PS从亚稳态聚集的重原子的无氮杂-BODIPY染料（BDP-1和BDP-2）轴承吡啶单元，这代表了高单线态氧（1 O2）的产生效率（高达0.85-0.89），以克服传统的重原子氮杂-BODIPY PS的几个固有的缺点。X射线晶体学分析和理论计算表明，分子间的多重静电相互作用触发了J-和H-聚集体的形成，从而改变了发色团的激发态性质，并通过减小单重态-三重态能隙（Δ EST）和辐射衰减促进了系间交叉（ISC）过程.本研究为通过巧妙的分子设计和工程技术阐明分子结构与聚集体性质之间的关系提供了新的见解，这将为构建PDT功能性聚集体开辟新的机会。
Aggregation of molecules offers a facile way to tune the optical properties of dyes, thus providing a design platform for organic nano-photosensitizers (PSs) with the potential in photodynamic therapy (PDT). However, it is still a great challenge to control the molecular organization of dye monomers to form a specific aggregation to maximize the efficiency of PDT. Herein, we present a novel supramolecular strategy to build nano-PSs from metastable aggregation of heavy-atom-free Aza-BODIPY dyes (BDP-1 and BDP-2) bearing pyridine units, which represented high singlet oxygen (1O2) generation efficiency (up to 0.85-0.89) to overcome the several intrinsic drawbacks of traditional heavy-atom Aza-BODIPY PSs. X-ray crystallographic analysis and theoretical calcula-tions revealed that multiple intermolecular electrostatic interactions triggered the formation of J-and H -ag-gregates, which transformed excited state properties of the chromophores and promoted the intersystem crossing (ISC) process by reducing singlet-triplet energy gaps (Delta EST) and radiative decay. This study provides insights for clarifying the relationship between molecular structure and aggregates properties by ingenious molecular design and engineering, which should open up new opportunities to construct functional aggregates for PDT.