Thermochromic Behavior of Azobenzene‐based Coordination Polymer with Reversible Breathing Process

Abstract

3 L = 5-(4-Sulfophenylazo) salicylic acid), was synthesized by a simple hydrothermal method. It reveals a 2D elastic layer-structured framework, forming a three-dimensional (3D) interlinked networks driven by extensive π…π stacking interactions. Removing water molecules by heating or vacuum freeze drying, it not only shows a reversible thermo-chromism but also exhibits a selective gas absorption and breathing effect. In addition, this material exhibits skeleton stability under reversible dehydra-tion/hydration. The reversible thermochromic behaviour is mainly attributed to the change of the coordination environment of Zn 2 + ions during the dehydration/hydration process. Furthermore, the film of 1 on the polylactic acid (PLA) support displayed similar reversible thermochromic behaviour with high sensitivity (large color-change and rapid response upon cooling or heating), promoting its application in switching fibres and devices, and naked-eye colorimetric sensor in the future.[a] W.

Multichromism in Halide Perovskites

“…[9][10][11] These smart windows offer new directions in building façade design due to their ability to regulate incoming sunlight. Meanwhile, organic compounds like azobenzenes, [12,13] spiropyrans, [11] diarylethenes, [14] helicenes, [15,16] and stilbenes [17] have been used to customize functionalities based on the structural diversity of materials. Stimulus-responsive polymers that alter color upon stimulation can react to various factors, including temperature (thermochromism), light (photochromism), stress (mechanochromism), pH (acidochromism and basochromism), electrical potential (electrochromism), pressure (piezochromism), solvation (solvatochromism), and water (hydrochromism).…”