Rationalizing the thermal response of dual-center molecular thermometers: the example of an Eu/Tb Coordination Complex

Abstract

Luminescence thermometry allows the remote monitoring of the temperature and holds the promise to drive the next generation of future nano or micrometric devices. Materials able to sense the temperature are usually based on one or several lanthanide ions allowing a ratiometric measurement. Optimizing the thermometric features is usually achieved through a serendipity approach, but it still appears difficult to accurately predict the sensing performance. Through a combination of experiment and theoretical calculations, the first example of an energy-driven luminescent molecular thermometer [Tb0.94Eu0.06(bpy)2(NO3)3] (bpy = 2,2′-bipydine) displaying an exceptional thermal cyclability around room temperature is reported, for which the thermal properties could be theoretically forecasted. This work provides comprehensive guidelines that can be easily extended for any dual-center thermometer in which energy transfer drives the thermometric performance opening the avenue for the smart engineering of sensing devices.