Developing Luminescent Ratiometric Thermometers Based on a Covalent Organic Framework (COF)

• Published in: Angewandte Chemie International Edition Vol. 59; no. 5; pp. 1932 - 1940
• Main Authors: Kaczmarek, Anna M., Liu, Ying‐Ya, Kaczmarek, Mariusz K., Liu, Hengshuo, Artizzu, Flavia, Carlos, Luís D., Van Der Voort, Pascal
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 27.01.2020
• Edition: International ed. in English
• Subjects: Acetylacetone; Covalent Organic Frameworks; Diamines; Lanthanides; Metal-organic frameworks; Porous materials; Quenching; Ratiometric Thermometers; Sensors; Thermometers; Sensors; Lanthanides; Ratiometric Thermometers; Covalent Organic Frameworks; Quenching
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201913983

Covalent Organic Frameworks (COFs), an emerging class of crystalline porous materials, are proposed as a new type of support for grafting lanthanide ions (Ln3+) and employing these hybrid materials as ratiometric luminescent thermometers. A TpBpy‐COF—prepared from 1,3,5‐triformylphloroglucinol (Tp) and 2,2′‐bipyridine‐5,5′‐diamine (Bpy) grafted with Eu/Tb and Dy acetylacetone (acac) complexes can be successfully used as a luminescent thermometer in the 10–360 K (Eu) and 280–440 K (Tb) ranges with good sensing properties (thermal sensitivity up to 1.403 % K−1, temperature uncertainty δT<1 K above 110 K). For the Eu/Tb systems, we observe an unusual and rarely reported behavior, that is, no thermal quenching of the Tb3+ emission, a result of the absence of ion‐to‐ligand/host energy back‐transfer. The LnCOF materials proposed here could be a new class of materials employed for temperature‐sensing applications following up on the well‐known luminescent metal–organic framework thermometers. A hot candidate: Covalent organic frameworks (COFs) are reported to be an excellent support for the grafting of lanthanide ions/complexes and allow the development of novel types of luminescent thermometers. A unique behavior, that is, no thermal quenching of the Tb3+ emission, is observed in these LnCOF materials.