Kinoshita Tomokazu, Nakamura Shunta, Harada Makoto, Hasobe Taku, Fukuhara Gaku
Department of Chemistry, Tokyo Institute of Technology 2-12-1 Ookayama, Meguro-ku Tokyo 152-8551 Japan
Department of Chemistry, Faculty of Science and Technology, Keio University Yokohama Kanagawa 223-8522 Japan
Chem Sci. 2023 Feb 23;14(12):3293-3301. doi: 10.1039/d3sc00312d. eCollection 2023 Mar 22.
Singlet fission (SF), which produces two triplet excitons from a singlet exciton, has been identified as a novel nanointerface for efficient (photo)energy conversion. This study aims to control exciton formation in a pentacene dimer through intramolecular SF using hydrostatic pressure as an external stimulus. We reveal the hydrostatic-pressure-induced formation and dissociation processes of correlated triplet pairs (TT) in SF by means of pressure-dependent UV/vis and fluorescence spectrometry and fluorescence lifetime and nanosecond transient absorption measurements. The photophysical properties obtained under hydrostatic pressure suggested distinct acceleration of the SF dynamics by microenvironmental desolvation, the volumetric compaction of the TT intermediate based on solvent reorientation toward an individual triplet (T), and pressure-induced shortening of T lifetimes. This study provides a new perspective on the control of SF by hydrostatic pressure as an attractive alternative to the conventional control strategy for SF-based materials.
单线态裂变（SF）可从一个单线态激子产生两个三线态激子，已被确定为一种用于高效（光）能量转换的新型纳米界面。本研究旨在通过使用静水压力作为外部刺激，通过分子内SF来控制并五苯二聚体中的激子形成。我们借助压力依赖的紫外/可见光谱和荧光光谱以及荧光寿命和纳秒瞬态吸收测量，揭示了SF中静水压力诱导的相关三线态对（TT）的形成和解离过程。在静水压力下获得的光物理性质表明，通过微环境去溶剂化、基于溶剂向单个三线态（T）重新定向的TT中间体的体积压实以及压力诱导的T寿命缩短，SF动力学明显加速。本研究为通过静水压力控制SF提供了一个新视角，这是基于SF的材料传统控制策略的一种有吸引力的替代方法。
