Fig. 3: Photochromism and fluorescence photoswitching of turn-on mode DAE derivatives.

a Molecular structures and photochromism of turn-on mode fluorescent DAE derivatives 5 and 6. b Absorption spectra of 5a (black dashed line), 5b (black solid line), and the photostationary state (PSS) under irradiation with 313 nm light (black dotted line) in 1,4-dioxane (2.0 × 10^–5 M) and the fluorescence spectrum of 5b (green solid line) under irradiation with 488 nm light. c Absorption spectra of 6a (black dashed line), 6b (black solid line), and PSS under irradiation with 365 nm light in 1,4-dioxane (1.0 × 10^–5 M) and the fluorescence spectrum of 6b (red solid line) under irradiation with 532 nm light. d Photographs of 1,4-dioxane solutions containing 5 and 6 before and after irradiation with 365 nm light under irradiation with 488 nm blue light (left-side solution containing 5) and 532 nm green light (right-side solution containing 6). (Reprinted with permission from Uno et al.²¹. Copyright 2011 American Chemical Society)