Selective Expression of Organic P hosphorescence Units: When H-Benzo[f]indole Meets 7H-Benzo[c]carbazole

作者：Xue Zhang, Chen Qian, Zhimin Ma, Zhimin Ma, Xiaohua Fu, Zewei Li, Huiwen Jin, Mingxing Chen, Zhiyong Ma, Zhiyong Ma · 发表于：Chemistry of Materials · 年份：2023 · DOI：10.1021/acs.chemmater.3c00193 · 被引用次数：34 · 研究领域：Luminescence and Fluorescent Materials、Organic Light-Emitting Diodes Research、Perovskite Materials and Applications

Phosphorescence selective expression in the development of ultralong organic room-temperature phosphorescence (UORTP) materials to enrich the properties and functions of smart materials is a very interesting topic but has not been realized yet due to the lack of organic phosphorescence units. In this work, we, for the first time, investigate the selective expression phenomenon of two organic phosphorescence units in a single molecule. First, we report a new phosphorescence unit 7 H -benzo[c]carbazole (BCz) with the advantage of simple synthesis. BCz derivatives (PNBCz-1 and PNBCz-2) feature photoactivated green ultralong phosphorescence in the PMMA film at room temperature, and cation radicals are involved in the unique ultralong phosphorescence behavior, which is similar to H -benzo[f]indole (Bd) derivatives. Different from Bd, pure powders of BCz derivatives show intense red-shifted ultralong phosphorescence at 77 K, probably due to the extended π conjugated structure of BCz. Then, BCz and Bd were incorporated into a single skeleton and two asymmetric molecules (PNBCzBd-1 and PNBCzBd-2) were obtained. Surprisingly, in the PMMA film, PNBCzBd-1 and PNBCzBd-2 both show photoactivated yellow ultralong phosphorescence at room temperature assigned to the intrinsic phosphorescence emission of Bd, and intrinsic green phosphorescence of BCz is almost screened by Bd. Density functional theory (DFT) calculations reveal that the incorporation of Bd leads to the shifting of the phosphor...