The excited-state intramolecular proton transfer (ESIPT) processes of 2-(2′-hydroxyphenyl)-benzothiazole (HBT) and salicylaldehyde imine (SAI) have been extensively studied. However, the ESIPT mechanism of HBT-coupled SAI was seldom reported. Herein, we synthesized a dye THER that integrating HBT and SAI, and investigated its excited-state dynamics in combination with femtosecond transient absorption spectrum and DFT/TDDFT calculations. Results indicate two proton transfer pathways could proceed in THER. The ESIPT rate in the HBT part is slower about 10-fold than in SAI part because of a relative higher energy barrier. Besides, torsion tends to occur after the ESIPT in the SAI part.

对2-（2'-羟基苯基）-苯并噻唑（HBT）和水杨醛亚胺（SAI）的激发态分子内质子转移（ESIPT）过程进行了广泛的研究。然而，很少报道HBT偶联SAI的ESIPT机制。在这里，我们合成了染料HIR和SAI结合在一起的染料THER，并结合飞秒瞬态吸收光谱和DFT / TDDFT计算研究了其激发态动力学。结果表明，在质子传递中有两种质子传递途径。由于相对较高的能垒，HBT部分中的ESIPT速率比SAI部分中的慢约10倍。此外，在SAI部分的ESIPT之后，容易发生扭转。