Switching thermally activated delayed fluorescence to room temperature phosphorescence for oxygen sensing: Effect of donor substituents of trifluoromethylphenyl

Levani Skhirtladze; Rasa Keruckiene; Oleksandr Bezvikonnyi; Malek Mahmoudi; Dmytro Volyniuk; Karolis Leitonas; Melika Ghasemi; Jurate Simokaitiene; Farah Hannan Abd Nasir; Azhar Ariffin; Juozas V Grazulevicius

doi:10.1016/j.saa.2023.123531

Switching thermally activated delayed fluorescence to room temperature phosphorescence for oxygen sensing: Effect of donor substituents of trifluoromethylphenyl

Spectrochim Acta A Mol Biomol Spectrosc. 2024 Feb 5:306:123531. doi: 10.1016/j.saa.2023.123531. Epub 2023 Oct 14.

Affiliations

¹ Department of Polymer Chemistry and Technology, Faculty of Chemical Technology, Kaunas University of Technology, K. Baršausko st. 59, LT-51423 Kaunas, Lithuania. Electronic address: Levani.skhirtladze@ktu.lt.
² Department of Polymer Chemistry and Technology, Faculty of Chemical Technology, Kaunas University of Technology, K. Baršausko st. 59, LT-51423 Kaunas, Lithuania.
³ Department of Polymer Chemistry and Technology, Faculty of Chemical Technology, Kaunas University of Technology, K. Baršausko st. 59, LT-51423 Kaunas, Lithuania; Department of Physics, Faculty of Mathematics and Natural Science, Kaunas University of Technology, Studentu˛ st. 50, LT-51369 Kaunas, Lithuania.
⁴ Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University Malaya, 50603 Kuala Lumpur, Malaysia.
⁵ Department of Chemistry, Faculty of Science, University Malaya, 50603 Kuala Lumpur, Malaysia.

PMID: 37890326
DOI: 10.1016/j.saa.2023.123531

Abstract

Two compounds consisting of electron-accepting trifluoromethylphenyl moiety and electron-donating phenoxazine and phenothiazine moieties were designed and synthesized via Buchwald-Hartwig coupling reaction. Thermal, photophysical, and electrochemical properties of the compounds are discussed. Only compound with phenothiazine form molecular glass, with glass transition temperatures of 90 °C. The geometry and electronic characteristics of the compounds were substantiated within density functional theory (DFT). 10,10'-(2-(Trifluoromethyl)-1,4-phenylene)bis(10H-phenoxazine) shows efficient thermally activated delayed fluorescence with high spin-orbit coupling values. 10,10'-(2-(Trifluoromethyl)-1,4-phenylene)bis(10H-phenothiazine) as efficient room-temperature phosphor shows high oxygen sensitivity.

Keywords: Dual emission; Phenothiazine; Phenoxazine; Room temperature phosphorescence; Trifluoromethylphenyl.