Vinyl Groups Containing Tetraphenylethylene Derivatives as Fluorescent Probes Specific for Palladium and the Quenching Mechanism

• 作者: Xiaoqing Liu Yuxuan Shang Zhong-Ren Chen
• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: Concise Reports
• 页码范围: 1599-1605
• 页数: 7页
• 语种: 英文
• DOI: 10.1002/cjoc.202000746

摘要

Main observation and conclusion We previously reported that a series of tetraphenylethylene(TPE)-containing all-hydrocarbon conjugated polymers exhibited a spe-cific fluorescence quenching by palladium ions(Pd2+).To understand the quenching mechanism,herein we investigate the quenching behaviors of three TPE derivatives in the presence of Pd2+.Each TPE derivative,consisting of TPE unit and terminal vinyl groups,shows an aggregation-induced emission(AIE)and its fluorescence turns off specifically to Pd2+.The sensitivity is enhanced with increasing numbers of vinyl groups in the molecules.By time-resolved fluorescence measurement,a dynamic quenching is observed where the fluorescence lifetime is reduced with Pd2+.Specifically,the quenching occurs via the electron transfer in the excited states,as sug-gested by the disappearance of the stimulated emission band in transient absorption spectra.A theoretical calculation on the excited states identifies intermolecular electron transfer from TPE derivatives to Pd,especially for electron-rich TPE derivative.The mecha-nism can be general for the design of novel AIE active chemosensors.