Multiwavelength-controlled multicolor photochromism and fluorescence switching based on an efficient photocyclization reaction by introducing two photoactive subunits into AIEgens

Abstract

Photochromic materials have recently attracted much attention in optoelectronic devices and optical storage systems because of their excellent reversible photoresponse performance. However, most traditional photochromic molecular systems have the limitation...

Recent advances in small-molecule fluorescent photoswitches with photochromism in diverse states

“…To overcome this problem, our group employed a new synthesis method to design a group of similar compounds in which two photochromic groups are located in cis conformation. 148 Introduction of two photoactive units greatly suppresses the AIE feature of these compounds, and significantly promotes their photochromic behaviours (Fig. 22).…”

Recent advances in photoresponsive fluorescent materials based on [2+2] photocycloaddition reactions

“…14–16 Among the various external stimuli, light is an ideal source with a high spatial and temporal resolution, clean, easy access, and simple operation. 17 Functional materials can spontaneously undergo structural transformations between at least two conformations through light-induced reversible or irreversible photochemical reactions with changes in physical properties such as viscosity, 18–20 shape, 21–24 fluorescence intensity, and colour 25–28 when irradiated by the light of a specific wavelength.…”

“…[14][15][16] Among the various external stimuli, light is an ideal source with a high spatial and temporal resolution, clean, easy access, and simple operation. 17 Functional materials can spontaneously undergo structural transformations between at least two conformations through light-induced reversible or irreversible photochemical reactions with changes in physical properties such as viscosity, [18][19][20] shape, [21][22][23][24] fluorescence intensity, and colour [25][26][27][28] when irradiated by the light of a specific wavelength. Among all response signals, fluorescent signals are increasingly gaining popularity in the research of light-stimulated responsive materials due to their designability, high sensitivity, and instantaneous visual feedback.…”

Photochemically Enhanced Emission by Introducing Rational Photoactive Subunits into an Aggregation‐Induced Emission Luminogen

“…However, when one phenyl group of tetraphenylethene is replaced by a photoactive thienyl subunit, a reversible photochromism behaviour can effectively take place for the luminogen as reported in our previous paper [45] . Differing from reversible photochromism of tetraarylethene containing dual thienyl subgroups with high efficiency, [46] the cooperation of introduced thienyl subunit and pyridyl subunit in tetraarylethene surprisingly achieves irreversible fluorescence photoactivation with very high efficiency in a very short time of UV irradiation. The molecule designed luminogen (Z)‐4‐(1,2‐double‐(4‐4‐methoxyphenyl) ‐2‐ (thiophene‐3‐group) vinyl) pyridine (BMPTP) shows transient solid‐state emission behaviour, and then undergoes highly efficient photocyclization‐dehydrogenation reaction with a conversion rate of nearly 100 %.…”