Excited State Properties of Lanthanide(III) Complexes with a Nonadentate Bispidine Ligand
Résumé
Eu III ,T b III ,G d III and Yb III complexes of the nonadentate bispidine derivative L 2 (bispidine = 3,7-diazabicyclo [3.3.1]nonane) were successfully synthesized and their emission properties studied. The X-ray crystallography reveals full encapsulation by the nonadentate ligand L 2 that enforces to all Ln III cations ac ommon highly symmetrical capped square antiprismatic (CSAPR) coordination geometry (pseudo C 4v symmetry). The well-resolved identical emission spectra in solid state and in solution confirm equal structures in both media. As therefore expected, this results in long-lived excited states and high emission quantum yields ([Eu III L 2 ] + ,H 2 O, 298 K, τ = 1.51 ms, ϕ = 0.35; [Tb III L 2 ] + ,H 2 O, 298 K, τ = 1.95 ms, ϕ = 0.68). Together with the very high kinetic and thermodynamic stabilities, these complexes are ap ossible basis for interesting biological probes.
Domaines
Chimie de coordination| Origine | Publication financée par une institution |
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