Zhang Beibei, Wei Lingzhong, Tang Xuansi, Jiang Zizhan, Guo Song, Zou Linmin, Xie Huihong, Gong Yongyang, Liu Yuanli
Guangxi Key Laboratory of Optical and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, China.
Materials (Basel). 2023 Jun 5;16(11):4193. doi: 10.3390/ma16114193.
Organic luminescent materials with high luminescence efficiency in both solution and solid states, namely dual-state emission (DSE), have attracted considerable attention due to their promising applications in various fields. In order to enrich the variety of DSE materials, carbazole, similar to triphenylamine (TPA), was utilized to construct a novel DSE luminogen named 2-(4-(9H-carbazol-9-yl)phenyl)benzo[d]thiazole (CZ-BT). CZ-BT exhibited DSE characteristics with fluorescence quantum yields of 70, 38 and 75% in solution, amorphous and crystalline states, respectively. CZ-BT shows thermochromic and mechanochromic properties in solution and solids, respectively. Theoretical calculations show that there is a small conformational difference between the ground state and the lowest singly excited state of CZ-BT and that it exhibits a low non-radiative transition characteristic. The oscillator strength during the transition from the single excited state to the ground state reaches 1.0442. CZ-BT adopts a distorted molecular conformation with intramolecular hindrance effects. The excellent DSE properties of CZ-BT can be explained well using theoretical calculations and experimental results. In terms of application, the CZ-BT has a detection limit for the hazardous substance picric acid of 2.81 × 10 mol/L.
在溶液和固态中均具有高发光效率的有机发光材料，即双态发射（DSE）材料，因其在各个领域的应用前景而备受关注。为了丰富DSE材料的种类，咔唑与三苯胺（TPA）类似，被用于构建一种新型的DSE发光体，名为2-(4-(9H-咔唑-9-基)phenyl)苯并[d]噻唑（CZ-BT）。CZ-BT在溶液、非晶态和晶态下分别表现出双态发射特性，荧光量子产率分别为70%、38%和75%。CZ-BT在溶液和固体中分别表现出热致变色和机械变色特性。理论计算表明，CZ-BT的基态和最低单重激发态之间存在微小的构象差异，并且其表现出低的非辐射跃迁特性。从单重激发态到基态跃迁过程中的振子强度达到1.0442。CZ-BT采用具有分子内位阻效应的扭曲分子构象。利用理论计算和实验结果可以很好地解释CZ-BT优异的双态发射特性。在应用方面，CZ-BT对有害物质苦味酸的检测限为2.81×10 mol/L。
