Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street No.2, Beijing, 100190, China.
University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing, 100049, P.R.China.
Angew Chem Int Ed Engl. 2023 Apr 3;62(15):e202300377. doi: 10.1002/anie.202300377. Epub 2023 Mar 2.
Understanding the influence of molecular structure on charge distribution and charge separation (CS) provides essential guidance for optoelectronic materials design. Here we propose a regioisomeric strategy to tune the diverse hole-distribution, and probe the influence on CS patterns. Para-, meta- and ortho-substituted benzidine-fullerene, named 1 p, 1 m and 1 o are designed. Following CS, hole-delocalization occurs in 1 p, while hole-localization exists in 1 m and 1 o. The rates of charge separation (4.02×10 s ) and recombination (9.8×10 s ) of 1 p is about 20 and 12 times faster than 1 m and 1 o, indicating that para-determined delocalization promotes ultrafast CS, while meta- and ortho-generated localization contributes to long-lived CS states. Computational analysis further implies that localization results from the destruction of electronic conjugation for 1 m, and limitation of conformational relaxation for 1 o. Given that the universality and simplicity of regional isomerism, this work opens up new thoughts for molecular design with tunable charge separation patterns.
了解分子结构对电荷分布和电荷分离（CS）的影响，为光电材料设计提供了重要指导。在这里，我们提出了一种区域异构体策略来调节不同的空穴分布，并探究其对 CS 模式的影响。设计了三种对位、间位和邻位取代的联苯-富勒烯，分别命名为 1p、1m 和 1o。CS 后，1p 中发生空穴离域，而 1m 和 1o 中发生空穴定域。1p 的电荷分离（4.02×10^s）和复合（9.8×10^s）速率分别比 1m 和 1o 快约 20 和 12 倍，表明对位决定的离域促进了超快 CS，而间位和邻位产生的定域有助于长寿命 CS 状态。计算分析进一步表明，1m 的定域是由于电子共轭的破坏，而 1o 的定域是由于构象弛豫的限制。鉴于区域异构体的普遍性和简单性，这项工作为具有可调电荷分离模式的分子设计开辟了新的思路。
