New Family of Luminescent Tetranuclear Lanthanide-Based Germsesquioxanes: Luminescence and Temperature Sensing

Abstract

We report the synthesis, structures, magnetic, and luminescence properties of a new series of tetranuclear lanthanide-based germsesquioxanes [NEt4]2[(Ph4Ge4O8)2(Ln4)(NO3)6(EtOH)2(MeCN)2]·n(CH3CN) (where Ln = Eu3+ (1), Tb3+ (2), Tb3+/Eu3+ (3), Dy3+/Y3+ (4), and Dy3+ (5)). These paramagnetic compounds exhibit characteristic Ln3+-based emission in solid state at room and liquid nitrogen temperature. Temperature-dependent luminescence investigated between 293 and 373 K reveals that mixed Tb3+/Eu3+ (3) compound works as a self-referenced ratiometric optical thermometer with a maximum relative sensitivity of 0.87%·°C–1 achieved at 57.6 °C.

Tetranuclear lanthanide-based silsesquioxanes: towards a combination of a slow relaxation of the magnetization and a luminescent thermometry

“…These results point at significant potential in design of functional metallasesquioxanes 47 including lanthanide centres. 48–50…”

Luminescent Ln3+-based silsesquioxanes with a β-diketonate antenna ligand: toward the design of efficient temperature sensors

“…Recently, we reported the first examples of luminescent Tb 3+ , Eu 3+ , and Dy 3+ -based metallasilsesquioxanes presenting unusual (for metallasilsesquioxanes) anionic prism-like structures. These structures encompass four Ln 3+ ions linked through oxygen atoms and situated between two cyclic tetraphenylcyclotetrasiloxanolate moieties ( Kulakova et al, 2020 ; Kulakova et al, 2021 ; Nigoghossian et al, 2021 ; Félix et al, 2023a ; Félix et al, 2023b ). They present Ln 3+ characteristic luminescence and interesting magnetic properties, depending on the nature of the ion, chemical robustness, and thermal stability.…”