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Vinyl Groups Containing Tetraphenylethylene Derivatives as Fluorescent Probes Specific for Palladium and the Quenching Mechanism †
Author(s) -
Liu Xiaoqing,
Shang Yuxuan,
Chen ZhongRen
Publication year - 2021
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.202000746
Subject(s) - chemistry , tetraphenylethylene , photochemistry , quenching (fluorescence) , fluorescence , palladium , excited state , intermolecular force , derivative (finance) , electron transfer , molecule , organic chemistry , catalysis , aggregation induced emission , physics , quantum mechanics , nuclear physics , financial economics , economics
Main observation and conclusion We previously reported that a series of tetraphenylethylene (TPE)‐containing all‐hydrocarbon conjugated polymers exhibited a specific fluorescence quenching by palladium ions (Pd 2+ ). To understand the quenching mechanism, herein we investigate the quenching behaviors of three TPE derivatives in the presence of Pd 2+ . Each TPE derivative, consisting of TPE unit and terminal vinyl groups, shows an aggregation‐induced emission (AIE) and its fluorescence turns off specifically to Pd 2+ . 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 Pd 2+ . Specifically, the quenching occurs via the electron transfer in the excited states, as suggested 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 mechanism can be general for the design of novel AIE active chemosensors.