Photochromic Dithienylethene‐Containing Boron(III) Ketoiminates: Modulation of Photo‐Responsive Behavior through Variation of Intramolecular Motion

Abstract

A series of dithienylethene-containing boron(III) ketoiminates, as well as their corresponding β-ketoimine ligands, have been synthesized and characterized. The photophysical, electrochemical, and photochromic properties of the compounds have been studied. Photocyclization has been found to be suppressed upon introduction of a phenyl substituent on the nitrogen atom of the β-ketoiminate core, whereas photochromism could be observed by replacement of the phenyl substituent with a bulky mesityl group. It is believed that the steric effect of the mesityl unit restricts molecular rotation, resulting in such a prominent difference in the photochromic properties.

Aggregation‐Induced Emission Luminogens with Photoresponsive Behaviors for Biomedical Applications

“…As AIEgens have been proven suitable for many different applications, to expand their range, a variety of photoresponsive AIEgens have also been developed, which have been applied in photopatterning, logic gates, anticounterfeiting, bioimaging, etc. [37] In general, three synthesis strategies have been proposed for photoresponsive AIEgens: incorporation of AIE cores with photoresponsive units, use of AIEgens with inherent photoreactions upon light irradiation, and use of AIEgens with tunable conformation upon light irradiation. These strategies are discussed individually in Subsections 3.1-3.3.…”

Photo‐Responsive Fluorescent Materials with Aggregation‐Induced Emission Characteristics

“…[86,87] In addition to the aforementioned examples, some photocyclization systems based on other AIEgens have been reported in recent years. [89][90][91] These investigations of the photocyclization properties of AIEgens provide new ideas for the subsequent construction of intelligent and efficient luminescent materials. It is important to develop more AIEgens with photocyclization activity and to understand the inherent mechanism, thereby promoting the development of advanced fluorescent materials and the exploitation of their application potential.…”

Photochromic dithienylethene-containing four-coordinate boron(iii) compounds with a spirocyclic scaffold

“…S28b, ESI†), which is comparable to other photochromic dithienylethene-containing four-coordinate boron( iii ) compounds. 26,27…”

“…8,9 In addition to the prevalently reported perfluorocyclopentene, a number of different heterocycles, such as 1,10phenanthroline, 10,11 thiazole, 12,13 thiophene, 14,15 imidazole, 16,17 benzothiadiazole, 18,19 silole 20 and phosphole, [21][22][23] have recently been introduced to the ethene backbone of diarylethene, establishing a wide variety of diarylethene derivatives with readily tuneable photochromism. In the meantime, coordination of diarylethene-containing ligands to metal centres 24,25 or heteroatoms 26,27 has been proven to be an effective method to enrich the photophysical and photochromic properties. The photochromism of these coordination complexes, to a certain extent, can also be perturbed by structural modifications of the ancillary ligands rather than the diarylethene-containing ligand, [27][28][29] which provides a convenient and versatile platform for preparing photochromic diarylethene-based photoresponsive materials without tedious synthetic procedures.…”