Organic doped red room-temperature afterglow materials based on 2,3,5-triarylfuro[3,2-b]pyridines through Förster-resonance energy transfer

Abstract

A series of novel 2,3,5-triarylfuro[3,2-b]pyridines are designed and acquired to be used as the guest molecules in organic doped room-temperature phosphorescence (RTP) system. Phenyl(pyridin-2-yl)methanone which can provide the rigid and tight microenvironment is chosen as the host molecule, which enables the two-component doped materials to emit RTP emissions of 0.5–8 s with 41–565 ms phosphorescence lifetimes and 2.9–19.4 % phosphorescence quantum efficiencies through constricting the non-radiative decay of triplet excitons. Furthermore, using commercial dyes Erythrosin B sodium salt and Eosin Y sodium salt as the third component and energy acceptor, the three-component materials emit bright red afterglows of 2 s with delayed lifetimes of 252–286 ms and emission quantum yields of 5.1–5.6 %, which are demonstrated to come from the triplet-to-singlet Förster-resonance energy transfer (FRET) from phosphorescence emission of 2,3,5-triarylfuro[3,2-b]pyridine derivative to fluorescence emission of commercial dye. This work not only provides valuable reference for the development of furo[3,2-b]pyridine-based afterglow materials, but also proves that the strategy of the FRET process provides new possibilities for molecules that can only emit fluorescence to participate in constructing afterglow materials.