New luminescent lanthanide complexes and Tb,Eu co-doped complex as a wide temperature self-calibrating thermometer

In this work, based on two ligands of 2,4-difluorobenzoic acid (2,4-DFBA) and 1,10-phenanthroline (phen), a series of new lanthanide complexes [Ln2(2,4-DFBA)6phen2, Ln = Tb 1a, Eu 1b, Gd 1c) and Tb,Eu co-doped complex [2, Tb1.976Eu0.0244(2,4-DFBA)6phen2] were successfully synthesized. It was found that 2 is an interesting multichannel readout pattern and self-calibrated temperature sensor, with a wide temperature sensing range in 77–300 K. It shows a high sensitivity up to 2.3%/K.