Red Room-Temperature Afterglow Emissions of Polymer-Based Doped Materials by Phosphorescence F?rster-Resonance Energy Transfer

摘要

A newly emerged and attractive strategy to obtain afterglow is the use of theF?rster-resonance energy transfer (FRET) from an energy donor withroom-temperature phosphorescence (RTP) to an energy acceptor withfluorescence. Due to the transfer of energy between molecules with differentemissions, it is possible to develop the ultralong and long-wavelengthafterglow materials. However, there are few reports on red afterglow materialswith emission wavelengths up to 650 nm because of the difficulty of accuratedesign of chemical structures. Herein, a series of red afterglow materials withemission wavelengths of 650 nm are constructed using polyvinylpyrrolidoneas the host, multisubstituted isoquinolines as the guests, andtriphenylamine-based dicyanomethylene-4H-pyran derivative as the energyacceptor. Two-component host-guest materials exhibit yellow-green, yellow,and orange RTP with delayed lifetimes of 205-301 ms and phosphorescencequantum yields of 5.3-13.2, which originate from the guests in a rigidmicroenvironment provided by the host polymer. Three-component dopedmaterials exhibit red afterglow with a delayed lifetime of 11-83 ms and anemission quantum yield of 16.2-22.1, which is determined to be delayedfluorescence caused by triplet-to-singlet FRET from isoquinolines todicyanomethylene-4H-pyran derivative. This work provides inspiration for thedevelopment of doped materials with long-wavelength room-temperatureafterglow.