In order to exploit novel fluorescent sensors with photoswitching properties, six fluorescent molecules were synthesized via coupling 1H-indole-7-carbohydrazide and corresponding substituted formaldehyde through an acylhydrazone bond. All title compounds were characterized via ¹H, ¹³C NMR, and elemental analysis, the single crystal structure of compound IC-PD was obtained via X-ray diffraction. The compounds IC-EL and IC-4PZ exhibited aggregation-induced emission (AIE) characteristics and also with regular responses to temperature and alkalinity in the solvent system dominated via deionized water. Probes IC-PL, IC-4PZ, and IC-PD could be used as fluorescence probes to detect copper (Ⅱ) with the LODs of 0.37, 0.27, and 0.26 μM in concentration of 0–50 μM, especially extraordinary bits of complex IC-PD-Cu²⁺ could also exhibited bright yellow in tetrahydrofuran (THF), which ensured the convenience of detection for Cu²⁺ ion. The exploration on the combination mechanism of representative compound IC-PD and Cu²⁺ ion via FT-IR and ¹H NMR, which confirmed that the proton of hydrazide was protonated via Cu²⁺ ion, resulting in the excited state intramolecular proton transfer (ESIPT) process was interfered. When IC-PD was irradiation to the 302 nm photostationary state (PSS), the fluorescence emission intensity of IC-PD in THF was slightly enhanced, accompanied with the increased sensitivity of detection for Cu²⁺. Although the improvement was not significant, it was also provided a design foundation for the development of stimuli responsive fluorescent materials with photoswitching properties.

为了开发具有光开关特性的新型荧光传感器，通过酰腙键偶联1 H-吲哚-7-碳酰肼和相应的取代甲醛，合成了六种荧光分子。所有标题化合物均通过 ¹ H、¹³ C NMR 和元素分析进行​​表征，通过X 射线衍射获得了化合物IC-PD的单晶结构。化合物IC-EL和IC-4PZ表现出聚集诱导发射 (AIE) 特性，并且对溶剂系统中的温度和碱度有规律的响应去离子水。探针IC-PL、IC-4PZ和IC-PD可作为荧光探针检测铜(Ⅱ)，在0-50 μM浓度下LOD分别为0.37、0.27和0.26 μM，特别是复杂IC的特殊位点-PD -Cu ²⁺在四氢呋喃(THF)中也能呈现亮黄色，保证了Cu ²⁺离子检测的方便性。通过FT-IR和¹ H NMR探索了代表性化合物IC-PD与Cu ²⁺离子的结合机理，证实酰肼的质子是通过Cu ^{2+质子化的}离子，导致激发态分子内质子转移（ESIPT）过程受到干扰。当IC-PD受到302 nm光稳态(PSS)照射时，IC-PD在THF中的荧光发射强度略有增强，同时对Cu ²⁺的检测灵敏度增加。虽然改进并不显着，但也为开发具有光开关特性的刺激响应荧光材料提供了设计基础。