Sensitization Pathways in NIR-Emitting Yb(III) Complexes Bearing 0, +1, +2, or +3 Charges - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of the American Chemical Society Année : 2022

Sensitization Pathways in NIR-Emitting Yb(III) Complexes Bearing 0, +1, +2, or +3 Charges

Jordann a L Wells
K. Eszter Borbas

Résumé

Yb(III) complexes of macrocyclic ligands based on 1,4,7,10-tetraazacyclododecane were synthesized. The ligands carried a carbostyril chromophore for Yb(III) sensitization, and carboxylate or carbamide donors for metal binding, forming complexes of 0, +1, +2, or +3 overall charge. The coordination geometry was little affected by the replacement of carboxylates with amides, as shown by paramagnetic 1H NMR spectroscopy. The Yb(III)/Yb(II) reduction potentials were dependent on the nature of the metal binding site, and the more positively charged complexes were easier to reduce. Carbostyril excitation resulted in Yb(III) luminescence in every complex. The residual carbostyril fluorescence quantum yields were smaller in complexes containing more reducible Yb(III) centers decreasing from 5.9% for uncharged complexes to 3.1–4.4% in +3 charged species, suggesting photoinduced electron transfer (PeT) from the antenna to the Yb(III). The relative Yb(III) luminescence quantum yields were identical within the experimental error, except for the +3 charged complex with fully methylated coordinating amides, which was the most intense Yb(III) emitter of the series in water. Quenching of the Yb(III) excited state by NH vibrations proved to limit Yb(III) emission. No clear improvement of the Yb(III) sensitization efficiency was shown upon faster PeT. This result can be explained by the concomitant sensitization of Yb(III) by phonon-assisted energy transfer (PAEnT) from the antenna triplet excited state, which was completely quenched in all of the Yb complexes. Depopulation of the triplet by PeT quenching of the donor singlet excited state would be compensated by the sensitizing nature of the PeT pathway, thus resulting in a constant overall sensitization efficiency across the series.
Fichier principal
Vignette du fichier
Mathieu, Sensitization Pathways in NIR-Emitting, 2022.pdf (3.37 Mo) Télécharger le fichier
Origine : Publication financée par une institution
Licence : CC BY - Paternité

Dates et versions

hal-04297298 , version 1 (21-11-2023)

Licence

Paternité

Identifiants

Citer

Emilie Mathieu, Salauat R Kiraev, Daniel Kovacs, Jordann a L Wells, Monika Tomar, et al.. Sensitization Pathways in NIR-Emitting Yb(III) Complexes Bearing 0, +1, +2, or +3 Charges. Journal of the American Chemical Society, 2022, 144 (46), pp.21056-21067. ⟨10.1021/jacs.2c05813⟩. ⟨hal-04297298⟩
13 Consultations
13 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More