Multifunctional broadband visible-light absorbing selenophene modified bodipy photosensitizers

作者：Tang, Liting; Lin, Dan; Rehmat, Noreen; Lu, Manlin; Mahmood, Zafar^*; Liang, Hui; Li, Ming-de^*; Zhao, Zujin^*; Huo, Yanping; Ji, Shaomin^*

来源：Dyes and Pigments, 2023, 217: 111392.

DOI：10.1016/j.dyepig.2023.111392

• Bodipy
• Intersystem crossing
• Triplet photosensitizer
• Triplet -triplet annihilation upconversion
• Photodynamic therapy

Large n-conjugated organic systems with effective photosensitization are highly desirable for many photo-chemical applications. Herein, a series of n-conjugated selenophene-substituted boron dipyrromethene (known as bodipy) dyes (MB-Se, 2B-Se, MB-Se-2Br) were prepared by appending selenophene electron-donor to the core of bodipy acceptors via alkynyl bridge and their excited state properties were investigated. Optical spectroscopy revealed that although these three selenophene-substituted bodipy dyes have nearly identical molecular profiles, their photophysical properties and excited state dynamics are drastically different. Higher triplet quantum ef-ficiency (& phi;& UDelta; = 82%) was observed for MB-Se, derivative in which & alpha;,& beta;-positions of bodipy decorated with methyl substituents, compared to another dye 2B-Se, which showed inefficient triplet population (& phi;& UDelta; = 25%). Employing steady-state absorption and emission spectroscopies, we demonstrated that the designed selenophene-substituted bodipy dyes has excellent J-aggregation capabilities. Notably, the J-aggregates of selenophene-substituted bodipy dyes display NIR emission. The potential of devised selenophene-substituted bodipy dyes in triplet fusion upconversion was also demonstrated; a blue upconverted emission was realized upon irradiating the mixture of bodipy dyes and TIPS-AC acceptor with 589 nm CW-laser. The selenophene-substituted bodipy dyes were also confirmed to be a potent photodynamic therapeutic reagent; with an IC50 value of 0.76 & mu;M, nearly 6 times lower than that of the iodide-appended bodipy photosensitizer (BDP-2I, 6.0 & mu;M). This study hopes to provide valuable guidelines for the future development of multipurpose triplet photosensitizers.

• 单位
  广东工业大学; 汕头大学