Photoswitchable turn-on mode fluorescent molecules have been so far successfully used in super-resolution fluorescence microscopies. Here, we report on fluorescence photoswitching of 1,2-bis(2-ethyl-6-phenyl-1-benzothiophene-1,1-dioxide-3-yl)perfluorocyclopentene (1) by irradiation with single-wavelength visible (420 nm < λ < 470 nm) light, the wavelength of which is longer than the 0–0 transition of open-ring isomer 1a, without UV light excitation. By absorbing very weak hot bands or Urbach tails 1a underwent a cyclization reaction to produce fluorescent closed-ring isomer 1b. Both cyclization and cycloreversion reactions of 1 took place with the visible light in the far off-resonance region of the absorption edge. Based on numerical simulations of the formation process of 1b from 1a by irradiation with 450 nm light, weak absorption coefficients at 450 nm in n-hexane and CCl₄ were estimated to be 0.084 and 0.19 M^–1 cm^–1, respectively. The reversible fluorescence photoswitching with the single visible light is advantageously applicable to super-resolution fluorescence imaging in biological systems.

中文翻译：

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单波长可见光照射对二芳基乙烯的荧光光开关

迄今为止，可光开关的开启模式荧光分子已成功用于超分辨率荧光显微镜检查中。在这里，我们通过可见光（420 nm）的辐射报告1,2-双（2-乙基-6-苯基-1-苯并噻吩-1,1-二氧化物-3-基）全氟环戊烯（1）的荧光光开关<λ<470 nm）的光，其波长长于开环异构体1a的0-0跃迁，没有紫外线激发。通过吸收非常弱的热带或Urbach尾巴1a进行环化反应，生成荧光闭环异构体1b。1的环化和环还原反应可见光发生在吸收边缘的非共振区域。基于所述形成过程的数值模拟1b中从1A通过用450nm的光，在450nm处的弱吸收系数照射Ñ正己烷和CCl ₄估计为0.084和：0.19M ^-1厘米^-1，分别。具有单个可见光的可逆荧光光开关有利地适用于生物系统中的超分辨率荧光成像。