Near‐Infrared Room‐Temperature Phosphorescence in Arylselanyl BODIPY‐Doped Materials

Abstract Near‐infrared (NIR) luminescent materials have received considerable attention owing to their intriguing applications in fields such as high‐resolution biological imaging and information technology. In this context, room‐temperature phosphorescence (RTP) materials with emission bands in the NIR region are rare. Metal‐free arylselanyl‐BODIPY triplet photosensitizers were doped into a benzophenone ( BP ) matrix. When excited at 350 nm, RTP emission was observed in the NIR region with λ em values of 750–816 nm, and the phosphorescence quantum yield was up to 0.48 %. The detection of an extremely large Stokes shift (≥400 nm) was responsible for the triplet‐triplet energy transfer from BP to the BODIPY guest. Furthermore, the RTP properties were tuned by derivatization of the selenium‐containing BODIPY guests. NIR‐RTP properties were also detected upon excitation at 470 nm with a persistent lifetime of up to 17.5 ms. Notably, in addition to NIR RTP emission, thermally activated delayed fluorescence was detected at 620 nm when 10 ms delayed spectra were measured for the MeOSeBOD ‐doped system. Considering the synthetic versatility of the BODIPY chromophore, this work opens up a new strategy for developing small molecule‐based NIR RTP systems.