Near-Infrared Room-Temperature Phosphorescence from Monocyclic Luminophores

• Published in: Angewandte Chemie International Edition 2024-11, p.e202417397
• Main Authors: Yan, Zi-Ang, Yin, Chenjia, Tian, He, Ma, Xiang
• Format: Article
• Language: English
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202417397

Compact luminophores with long emission wavelengths have aroused considerable theoretical and practical interest. Organics with room-temperature phosphorescence (RTP) are also desirable for their longer lifetimes and larger Stokes shifts than fluorescence. Utilizing the low electronic transition energy intrinsic to thiocarbonyl compounds, electron-withdrawing groups were attached to the 4H-pyran-4-thione core to further lower the excited state energies. The resulting mini-phosphors were doped into suitable polymer matrices. These purely organic, amorphous materials emitted near-infrared (NIR) RTP. Having a molar mass of only 162 g mol , one of the phosphors emitted RTP that peaked at 750 nm, with a very large Stokes shift of 15485 cm (403 nm). Thanks to the good processability of the polymer film, light-emitting diodes (LEDs) with NIR emission were easily fabricated by coating doped polymer on ultraviolet LEDs. This work provides an intriguing strategy to achieve NIR RTP using compact luminophores.