Reinforced Donor-Acceptor Type Dithienylethene with Aggregation-Induced Emission for Visible Light-Triggered Photoswitching Behavior in Aqueous Media

Abstract

The development of visible light-triggered photochromic dithienylethene (DTE) derivatives with aggregation-induced emission (AIE) feature is extremely attractive for biological scenarios and photoelectric materials. Herein, we have developed a novel carbazole and cyanostilbene-functionalized DTE derivative (Cz-DTE-CN) with a reinforced donor (D)-DTE-acceptor (A) structural feature, in which cyanostilbene fragment exerts both electron-withdrawing and AIE effect and the carbazole moiety functions electron-donating group. Such structural features confers it efficient visible light-driven photochromism and AIE properties. The corresponding chemical structure is confirmed via 1H NMR, 13C NMR and HRMS. As predicted, Cz-DTE-CN is demonstrated efficient photoswitching behavior in various solvents and solid state upon alternating irradiation with 420 nm purple light and 660 nm red light. Cz-DTE-CN shows AIE performance in a mixed solution of H2O/THF before purple light irradiation. Furthermore, the water-soluble nanoparticles (Cz-DTE-CN NPs) encapsulated by the amphiphilic Pluronic F127 also shows excellent photoswitching performance. The density functional theory (DFT) calculations further verifies the photochromic experimental results. Therefore, this DTE derivative may be applied in functional biomaterials as the promising photochromic materials.

Keywords: dithienylethene, photochromism, donor-acceptor, cyanostilbene, aggregation-induced emission (AIE), visible light