Kim Min-Ji, Ahn Mina, Chae Minjung, Kim Sanghyun, Kim Daehoon, Wee Kyung-Ryang
Department of Chemistry, Institute of Natural Science, Daegu University Gyeongsan 38453 Republic of Korea
RSC Adv. 2021 Oct 28;11(55):34945-34954. doi: 10.1039/d1ra06602a. eCollection 2021 Oct 25.
A series of -terphenyl linked donor-π-acceptor (D-π-A) dyads were prepared to understand the electronic effects of a -terphenyl linker according to the electron-accepting ability change. The energy band gaps of the dyads were controlled by tuning the accepting ability, which resulted in emission colors ranging from blue-green to red. In the Lippert-Mataga plots, intramolecular charge transfer (ICT) behavior was observed, which showed gradually increased ICT characteristics as the accepting ability was increased. On the other hand, in the absorption spectra, a red shift of the ICT transition was observed differently from the electron-accepting ability tendency. Thus, the experimental results show that the ICT is determined by steric hindrance rather than the acceptor ability in the ground state due to the lack of π-conjugation of the terphenyl linker by the electron node in the -position, whereas ICT in the excited state is controlled by electron-accepting ability.
制备了一系列联苯相连的供体-π-受体（D-π-A）二元化合物，以根据电子接受能力的变化了解联苯连接基的电子效应。通过调节接受能力来控制二元化合物的能带隙，这导致发射颜色从蓝绿色到红色不等。在Lippert-Mataga图中，观察到分子内电荷转移（ICT）行为，随着接受能力的增加，ICT特征逐渐增强。另一方面，在吸收光谱中，观察到ICT跃迁的红移与电子接受能力趋势不同。因此，实验结果表明，由于在对位的电子节点对联苯连接基缺乏π共轭，ICT在基态由空间位阻而非受体能力决定，而激发态的ICT由电子接受能力控制。
