Dvylys, LukasLukasDvylysKeruckiene, RasaRasaKeruckieneGuzauskas, MatasMatasGuzauskasChu, Shi-WeiShi-WeiChuGrazulevicius, Juozas V.Juozas V.Grazulevicius2026-01-062026-01-062025-05https://scholars.lib.ntu.edu.tw/handle/123456789/735066In this work, we present two very sensitive new heavy metal-free thianthrene-based oxygen analytes. Experimental results in combination with theoretical calculations, confirm that both the compounds display room-temperature phosphorescence, with a significant difference in intensity observed in air and oxygen-free environments. The compounds show long emission lifetimes reaching up to 27.08 ms. This indicates the involvement of oxygen-sensitive triplet emission which occur due to intersystem crossing. The compounds show record-high Stern-Volmer constants, reaching 1.57 × 10−2 ppm−1. These properties suggest that 2-(pentan-3-yl)-6-(anthracen-1-yl)-1H-benzo[de]isoquinolin-1,3(2 H)-dione and 4-(thianthren-1-yl)benzonitrile are perfect candidates for metal-free oxygen sensors with one of the highest sensitivity detection at low oxygen concentrations reported so far.Oxygen sensingRoom temperature phosphorescenceThianthrene[SDGs]SDG3journal article10.1016/j.snb.2025.137380