Recent Advances in the Z/E Isomers of Tetraphenylethene Derivatives: Stereoselective Synthesis, AIE Mechanism, Photophysical Properties, and Application as Chemical Probes

Abstract

Focused research on the Z/E isomerso ft etraphenylethene (TPE) derivatives is scarce in comparison with the thousands of luminogens with AIE properties (AIEgens) that have been synthesized based on the TPE moiety.T he similar chemical and physical properties of the Z/E isomersm ake them difficult to separate by using conventional chromatographic techniques.H owever,t hey can be isolated by introducing polar groupsa nd the pure isomers exhibit very different photophysical properties, mechanochromism, and host-guestc oordination,a sw ell as assisting in deciphering the AIE mechanism. In this Minireview, we present an overview of the disagreement regarding the AIE mechanism between the restriction of intramolecular vibration and photoinduced Z/E isomerization. Then, we discuss the development of (Z)-/(E)-TPE derivatives, their use in host-guest detection, and their mechanoluminescence properties, with a focus on their photophysical characteristics. Finally,w ee xplore the stereoselective synthesis of pure (Z)-/(E)-TPE derivatives.

Photo‐Responsive Fluorescent Materials with Aggregation‐Induced Emission Characteristics

“…[96,97] By virtue of the advantages of easy operation and convenient regulation, photoinduced E/Z isomerization offers a unique avenue into research on the characteristics and connections of these materials, which is important for exploring practical applications. [29,98,99] Wong et al used simple reactions to synthesize a series of photo-responsive difluoroboron-based green fluorescent protein analogues (BOAHY) with AIE properties. [100] These BOAHYs all adopted the Z-form except for compounds 2e and 2f.…”

“…In recent years, a series of such materials has been developed. [29,30] The various transformations in the chemical structures of AIE materials following photoreaction are always translated into changes in photophysical properties, endowing them with novel properties and wide applications. On the one hand, grafting AIE fluorogens (AIEgens) into photochromic molecules is one of the most effective strategies to construct photo-responsive AIE materials.…”

Light-gated nano-porous polymersomes from stereoisomer-directed self-assemblies

“…The structures of all the compounds were con rmed by 1 H NMR, 13 C NMR and high-resolution mass spectrometry (HRMS) ( Fig. S4-S9, Fig.…”

Suzuki-Miyaura Coupling Enabled by Aryl to Vinyl 1,4-Palladium Migration

“…Notably, multi-aryl substituted olefins and 1,3-dienes may display interesting electronic and photonic properties owing to their p-extended systems and have been widely applied in many diverse fields, such as chemical or biological sensors, stimuli response material, and fluorescent materials ( Figure 1C) (Kong et al, 2018;Yang et al, 2014;He et al, 2019). Despite the fact that the geometry of double bonds in these molecules has great influence on the material performance, effective synthetic approaches toward these structures remain to be limited, in which the application of symmetric starting material or a homo-coupling reaction is often necessary to overcome the geometric problem (Xie and Li, 2019;Zhang et al, 2016b).…”