Ma Jie, Zhang Yizhi, Zhang Hongbo, He Xifeng
Heilongjiang Provincial Key Laboratory of Catalytic Synthesis for Fine Chemicals, College of Chemistry and Chemical Engineering, Qiqihar University Qiqihar 161006 P. R. China
RSC Adv. 2020 Sep 30;10(59):35840-35847. doi: 10.1039/d0ra07050e. eCollection 2020 Sep 28.
The dyes (P-1 and P-2) of perylenebisimide (PBI) conjugated with 2-(2-hydroxyphenyl)benzothiazole (HBT) were prepared by Sonogashira coupling reaction. The new compounds have special photophysical properties, such as near infrared absorption/emission and large Stokes shift. The UV-vis absorption (range from 651 nm to 690 nm) and emission wavelength (range from 732 nm to 756 nm) of P-1 and P-2 extend to near infrared range. Importantly, they have much larger Stokes shifts (range from 73 nm to 105 nm) compared with the conventional PBI derivatives, such as 7 (from 19 nm to 65 nm) and 9 (from 81 nm to 86 nm). TD-DFT calculation was used to rationalize UV-vis absorption, emission and especially large Stokes shift from the theoretical point of view. We found geometry relaxation of P-1 and P-2 in the excited state is an important reason for the origin of large Stokes shift besides intramolecular electron transfer (ICT).
通过Sonogashira偶联反应制备了与2-(2-羟基苯基)苯并噻唑(HBT)共轭的苝二酰亚胺(PBI)染料(P-1和P-2)。这些新化合物具有特殊的光物理性质，如近红外吸收/发射和大斯托克斯位移。P-1和P-2的紫外可见吸收(范围为651 nm至690 nm)和发射波长(范围为732 nm至756 nm)延伸至近红外范围。重要的是，与传统的PBI衍生物(如7，范围为19 nm至65 nm；9，范围为81 nm至86 nm)相比，它们具有大得多的斯托克斯位移(范围为73 nm至105 nm)。采用TD-DFT计算从理论角度解释紫外可见吸收、发射以及特别是大斯托克斯位移。我们发现，除了分子内电子转移(ICT)外，P-1和P-2在激发态的几何弛豫是大斯托克斯位移产生的一个重要原因。
