Exploring the reaction coordinates for f-f emission and quenching of lanthanide complexes - Thermosensitivity of terbium(III) luminescence

Lanthanide complexes with temperature dependent f-f emission intensities are commonly used as temperature sensors. The thermosensitivity can be controlled by the ligands, but their effects are difficult to predict. To clarify the origin of the differences in thermosensitivity, we propose a new theoretical strategy, the energy shift method, and use it to find crossing points between two states where intersystem crossing and excitation energy transfer take place. The different sensitivities of the three studied terbium(III) complexes are caused by the different rate-determining steps for emission or quenching.