Fig. 3.

The mechanism investigation of visible-light-driven DAE-o-DT. a Photocyclization performances of DAE-DT (2.0 × 10⁻⁵ M) in argon bubbling toluene (black square), oxygen bubbling toluene (red circle) and toluene with triplet quencher anthracenes (1.0 mM, blue triangle), respectively. b Transient absorption decays of DT (1.0 × 10⁻⁴ M) and DAE-o-DT (1.0 × 10⁻⁴ M) at 620 nm. c The luminescence lifetime spectra of DT (2.5 × 10⁻⁴ M) and DAE-o-DT (2.5 × 10⁻⁴ M) at 495 nm. d The emission decays of DT (2.5 × 10⁻⁴ M) and DAE-o-DT (2.5 × 10⁻⁴ M) at 77 K in toluene. e Frontier molecular orbitals of DAE-o-DT and DT by B3LYP functional and the 6-31 G(d) basis set, respectively