Gao Jiaan, Yang Min, Mu Hongyan, Guan Xiaotong, Zhang Yifu, Li Hui, Liu Hongxu, Jin Guangyong
Jilin Key Laboratory of Solid-State Laser Technology and Application, School of Physics, Changchun University of Science and Technology, Changchun 130022, China.
Jilin Key Laboratory of Solid-State Laser Technology and Application, School of Physics, Changchun University of Science and Technology, Changchun 130022, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2024 Dec 5;322:124866. doi: 10.1016/j.saa.2024.124866. Epub 2024 Jul 22.
The triphenylamine Schiff-base (TPASB) with dual proton transfer sites (N…H-O [R1] and N…H-O [R2]), which is crucial in the field of optoelectronic materials. Herein, a novel molecular design strategy for preparing of TPASB-1 and TPASB-2 via the selective methylation of the hydroxyl group at the R2 or R1 position was proposed. The analysis of electronic structures and potential energy surfaces revealed that a single excited state intramolecular proton transfer (ESIPT) process of TPASB occurs only at R1. Nevertheless, the ESIPT process of TPASB-2 was successfully turned on at R2. More noteworthy is that compared to TPASB, the methylation of hydroxyl group at the R2 position triggers the TICT process of TPASB-1, effectively reducing the potential barrier of ESIPT at the R1 position. This theoretical study explains the role of the substituent effect in regulating ESIPT behaviour, and provides valuable guidance for synthesising efficacious ESIPT-active compounds.
具有双质子转移位点（N…H-O [R1] 和 N…H-O [R2]）的三苯胺席夫碱（TPASB）在光电子材料领域至关重要。在此，提出了一种通过对 R2 或 R1 位置的羟基进行选择性甲基化来制备 TPASB-1 和 TPASB-2 的新型分子设计策略。电子结构和势能面分析表明，TPASB 的单重激发态分子内质子转移（ESIPT）过程仅在 R1 处发生。然而，TPASB-2 的 ESIPT 过程在 R2 处成功开启。更值得注意的是，与 TPASB 相比，R2 位置羟基的甲基化触发了 TPASB-1 的 TICT 过程，有效降低了 R1 位置 ESIPT 的势垒。这项理论研究解释了取代基效应在调节 ESIPT 行为中的作用，并为合成有效的 ESIPT 活性化合物提供了有价值的指导。
