Chalcogen Effect of Atom Substitution on the Properties of Tris(2,4,6-trichlorophenyl)methyl(TTM) Radical

作者：Yang, Yiming; Qiu, Lili; Shi, Xueliang^*

来源：CHEMICAL RESEARCH IN CHINESE UNIVERSITIES, 2023, 39(2): 197-201.

DOI：10.1007/s40242-023-3008-2

• Luminescent organic radical
• Chalcogen atom effect
• Photoluminescence quantum yield(PLQY)
• Photostability
• Electron paramagnetic resonance(EPR)

Luminescent open-shell organic radicals have recently been regarded as one of the most potential materials in organic light-emitting diodes(OLEDs). Herein, we have synthesized two new organic radicals, namely tris{4-[4-(tert-butyl)phenoxy]-2,6-dichlorophenyl}methane radical(TTM-O) and tris(4-{[4-(tert-butyl)-phenyl]thio}-2,6-dichlorophenyl)methane radical(TTM-S), by the substitution of chalcogen atom elements at the para position of conventional tris(2,4,6-trichlorophenyl)methyl(TTM) radical moiety. Interestingly, both TTM-O and TTM-S exhibited significantly enhanced photostability compared with the unsubstituted TTM radical parent. Moreover, the chalcogen atom also had a crucial impact on the photoluminescence quantum yield(PLQY) of the radicals, i.e., the PLQY of TTM-S was greatly enhanced compared to TTM radical while TTM-O was nearly non-emissive. Particularly, TTM-S showed intense PLQY of 37.54% and 185-fold longer photostability than that in cyclohexane solution of TTM.