Light-responsive organic functional materials, including photochromic materials and room temperature phosphorescent materials, have attracted significant attention in recent years due to their excellent performance. However, most reported light-responsive organic materials have single functions and typically require ultraviolet light activation, which significantly limits their applications in fields such as multi-channel information storage. Therefore, developing multifunctional organic materials, especially those that can be excited by visible light, has become an important research direction. However, due to the dynamic competition between the photochemical reactions of photochromism and the room temperature phosphorescence process when the materials are light-excited, developing materials that can simultaneously achieve both photochromic and room temperature phosphorescent properties faces significant challenges.
Recently, the team of Academician Huang Wei and Professor Yu Tao from Northwestern Polytechnical University constructed a series of visible light excited organic photochromic room temperature phosphorescent materials (DBTDpH@EA:AA, DBTDpF@EA:AA, and DBTDpCl@EA:AA) by endowing organic photochromic materials with room temperature phosphorescent properties, combining local rigidity design strategies with host-guest strategies. By introducing diphenylbenzothiophene into the triphenyl ethylene framework to construct a closed-loop state extended π-conjugated system, a red shift of the absorption peak and excitation spectrum was achieved. The rich intermolecular interactions generated by halogen atoms and distorted molecular conformations, along with the effects of the polymer matrix, effectively stabilized the triplet excitons and reduced energy dissipation, thereby simultaneously endowing the materials with visible light excited photochromism and room temperature phosphorescence properties. In addition, related photophysical studies, single crystal analysis, and density functional theory (DFT) calculations were conducted to elucidate the internal mechanisms of the visible light excited organic photochromic room temperature phosphorescent materials and propose design strategies for this new type of smart material. The research results were recently published in the top international journal J. Am. Chem. Soc. under the title “3D Printable Materials with Visible Light Triggered Photochromism and Room Temperature Phosphorescence.” PhD student Xiao Yuxin and master’s student Li Jiahui from Northwestern Polytechnical University are co-first authors of this paper, while Academician Huang Wei and Professor Yu Tao are co-corresponding authors.
The research indicates that this series of materials can achieve precise three-dimensional structure fabrication with digital light processing (DLP) 3D printing technology. Based on this, the work also achieved concentration-dependent information encryption as shown in the figure below. This work provides a material basis for advanced information storage and three-dimensional structure construction.
Article link:
https://pubs.acs.org/doi/10.1021/jacs.5c00976
Text: Xiao Yuxin
Editor: Wang Qing
Review: Wang Xuewen
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