A turn-on mode fluorescent diarylethene: Solvatochromism of fluorescence. (June 2018)

• Record Type: Journal Article
• Authors: Morimoto, Masakazu; Takagi, Yuta; Hioki, Karina; Nagasaka, Tatsuhiro; Sotome, Hikaru; Ito, Syoji; Miyasaka, Hiroshi; Irie, Masahiro
• Is Part Of: Dyes and pigments. Volume 153(2018)
• Page Start: 144
• Page End: 149
• Publication Date: 2018-06
• Subjects: Fluorescence -- Sovatochromism -- Photochromism -- Diarylethene; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2018.02.016
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: Environment-sensitive fluorophores have been used as molecular probes to acquire physical and chemical information in microstructures. Here, we report on solvatochromism of a fluorescent diarylethene, which is switched by photoirradiation. A turn-on mode photoswitchable fluorescent diarylethene derivative, 1, 2-bis(2-ethyl-6-(5-methylthiophen-2-yl)-1-benzothiophen-1, 1-dioxide-3-yl)perfluorocyclopentene (1a ), underwent a cyclization reaction upon irradiation with ultraviolet (UV) light to form fluorescent closed-ring isomer1b .1b dramatically changed the fluorescent color in response to solvent polarity, such as green in n -hexane, yellow in tetrachloromethane (CCl4 ), orange in dichloromethane (CH2 Cl2 ), and red in dimethyl sulfoxide (DMSO), and showed high fluorescence quantum yields of 0.6–0.8 in these solvents. The fluorescent solvatochromism is ascribed to the intramolecular charge-transfer (ICT) character of1b, which consists of electron-donating thiophene rings at both ends and central electron-accepting benzothiophene 1, 1-dioxide groups. The analysis based on the Mataga-Lippert plot revealed that the difference in the dipole moments between the excited and ground states of1b is as large as 12 D. Such a solvatochromic fluorophore with photoswitching ability can find potential applications in super-resolution fluorescence imaging of microscopic polarity in biological cells and materials. Graphical abstract: Highlights: A diarylethene derivative undergoes turn-on mode fluorescence switching upon irradiation with ultraviolet light. The closed-ring isomer changes its fluorescent color in response to solvent polarity and shows high fluorescence quantum yields of 0.6–0.8. The fluorescence solvatochromism is ascribed to the intramolecular charge-transfer character of the closed-ring isomer.