Cryogenic Luminescent Tb/Eu-MOF Thermometer Based on a Fluorine-Modified Tetracarboxylate Ligand
journal contributionposted on 26.09.2018, 12:33 by Dian Zhao, Dan Yue, Ling Zhang, Ke Jiang, Guodong Qian
A fluorine-modified tetracarboxylic acid ligand, namely, 2′-fluoro-[1,1′:4′,1′′-terphenyl]-3,3′′,5,5′′-tetracarboxylic acid (H4FTPTC), with suitable triplet energy excited state, was designed and applied to construct the luminescent lanthanide metal–organic frameworks (LnMOFs) for cryogenic temperature sensing. With the lanthanides codoping strategy, we developed a new Tb3+/Eu3+ mixed LnMOF system Tb1–xEuxFTPTC (x = 0.05, 0.1, 0.2), which feature excellent linear responses to temperature with high relative sensitivity in the cryogenic range of 25–125 K. It was found that the relative sensitivity of such mixed LnMOF could readily be tuned by adjusting the incorporation amount of Eu3+ ions in the host framework. In addition, the energy transfer efficiency between the Tb3+ and Eu3+ ions in the framework with different Tb3+/Eu3+ ratios are also investigated and discussed.