Ruthenium-catalyzed C-H bond activation and annulation of phenothiazine-3-carbaldehydes: facile access to dual-emission materials.

Reported herein is the first example of a ruthenium-catalyzed C-H activation/annulation of phenothiazine-3-carbaldehydes to construct structurally diverse pyrido[3,4-]phenothiazin-3-iums with dual-emission characteristics. Novel organic single-molecule white-light materials based on pyrido[3,4-]phenothiazin-3-iums with dual-emission and thermally activated delayed fluorescence (TADF) characteristics have been developed for the first time herein. Furthermore, the dual-emission molecule could be fabricated as water-dispersed NPs, which could be applied in two-channel emission intensity ratio imaging to observe the intercellular structure and can specifically target the cell membrane.