Conformation‐Controlled Double Phosphorescence Components From A Single Organic Molecule: Time‐Dependent and Excitation‐Dependent Wide‐Range Afterglow Color Change

作者：Jingjuan Bai, Lin Han, Yiran Liu, Lijuan Bu, Shui Hu, Jiaxin Ma, Zewei Li, Mingxing Chen, Zhimin Ma, Zhiyong Ma, Zhiyong Ma, Zhiyong Ma · 发表于：Advanced Functional Materials · 年份：2024 · DOI：10.1002/adfm.202411496 · 被引用次数：41 · 研究领域：Luminescence and Fluorescent Materials、Organic Light-Emitting Diodes Research、Molecular Sensors and Ion Detection

Abstract Double phosphorescence components from a single organic molecule is rarely reported before because most organic molecules must follow Kasha's rule and merely emit phosphorescence from T 1 state. We discover a unique phenomenon of conformation‐controlled expression of double phosphorescence components. The green phosphorescence component and the red phosphorescence component are assigned to the dinaphthylamine moiety and the pyrene unit of N,N‐di(naphthalen‐2‐yl)pyren‐1‐amine (NaPy), respectively. NaPy shows time‐dependent and excitation‐dependent afterglow color change in copolymerized MMA film at room temperature due to simultaneous expression of the double phosphorescence components. However, in PMMA film and copolymerized MA film, NaPy just expresses the red phosphorescence component, suggesting that matrix rigidity greatly affects expression of the double phosphorescence components via altering conformation of NaPy. In low‐rigidity matrix, the NaPy conformation is dyanmic due to free rotation and triplet excitons relax to T1 state via inner conversion or vibration relaxation, leading to the sole expression of the red phosphorescence component. In high‐rigidity matrix, the highly twisted conformation of NaPy is stabilized due to limitation of rotation and triplet excitons at T 1 state and T 2 state return to S0 state separately, resulting in simultaneous expression of the double phosphorescence components. Thus, NaPy follows Kasha's rule in low‐rigidity matrix but...