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Comprehensive Summary Salicylaldehyde Schiff base is a kind of important photochromism system, whose photochromism process is widely acknowledged to be co‐determined by the electronic structure and molecular conformation. Normally, salicylaldehyde Schiff base derivatives with α‐type structures tend to exhibit photochromism while those with β‐type structures tend to be photostable. However, more and more counterexamples are found, and the root cause of photochromism property of salicylaldehyde Schiff base is still unclear. In this work, a series of chiral salicylaldehyde Schiff bases and their racemates were prepared. The formers are photochromic while the latters are photostable. Influenced by Wallach's rule, the homochiral counterparts have looser packing modes than that of the racemic counterparts. Mechanism study revealed that the pressure should be the root cause of photochromism property. Close molecule packing can restrict the photochromism property effectively after being pressed, which also explains why the photochromism of salicylaldehyde Schiff base is usually observed in solid state. This work not only reports the unique photo‐responsive difference between the chiral salicylaldehyde Schiff bases and their racemates, more importantly, provides a new perspective to understand the influence of molecule pressure on their photophysical properties. [ABSTRACT FROM AUTHOR]

Nanomaterials with intrinsic enzyme mimicking activity have achieved widespread application. However, developing novel nanomaterials with multienzyme mimicry activity remains challenging. Herein, Cu 3 (HITP) 2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) with ascorbic acid oxidase (AAO)- and peroxidase (POD)-like activity are successfully synthesized. Cu 3 (HITP) 2 exhibits excellent AAO-like activity and can specifically catalyze the oxidation reaction of ascorbic acid (AA). Dehydroascorbic acid (DHAA) obtained from the oxidation of AA is allowed to react with nonfluorescent o-phenylenediamine (OPD) to form 3-(1,2-dihydrox-yethyl) furo[3,4-b]quinoxaline-1-one (DFQ) with strong fluorescence emission. Moreover, Cu 3 (HITP) 2 is able to catalyze the chemiluminescence (CL) reaction of ABEI-H 2 O 2 to generate a strong and glow-type emission based on its POD activity. Inspired by the multienzyme mimicry activity of Cu 3 (HITP) 2 , the simple and sensitive fluorescence and chemiluminescence sensing platforms are successfully constructed and applied for the detection of AA. The sensors show high sensitivity and excellent selectivity. We believe that this multienzyme mimicry activity nanomaterial not only can be used to construct the multiple-mode biosensing platform, but also enables the extensive applications in the fields of biomedicine, energy, and environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)