Molecular Upconversion in Water in Heteropolynuclear Supramolecular Tb/Yb Assemblies.

Fiche publication


Date publication

janvier 2019

Journal

Journal of the American Chemical Society

Auteurs

Membres identifiés du Cancéropôle Est :
Dr CHARBONNIERE Loïc, Pr MELY Yves


Tous les auteurs :
Nonat A, Bahamyirou S, Lecointre A, Przybilla F, Mély Y, Platas-Iglesias C, Camerel F, Jeannin O, Charbonnière LJ

Résumé

Piling up excited states to reach upconversion (UC) is severely restricted by vibrational quenching mechanisms, especially when one looks at discrete molecular entities in solution. By carefully controlling the supramolecular assembly processes resulting from the strong electrostatic interactions between negatively charged Yb complexes and Tb cations in aqueous solutions, we engineered the formation of heteropolynuclear complexes of [(YbL)Tb ] compositions ( x = 1 and 2). These edifices display a phenomenon of cooperative photosensitization UC with green emission of the Tb cations upon NIR excitation at 980 nm in the Yb absorption band. The photophysical properties of the complexes were carefully investigated by steady-state and time-resolved luminescence experiments in DO, allowing one to quantify the impact of the composition and pD of the solution on the emission intensity as well as clarifying the exact cooperative photosensitization upconversion mechanism. Using optimized conditions, the energy transfer UC process could be observed for the first time in nondeuterated water with discrete molecular compounds.

Référence

J. Am. Chem. Soc.. 2019 Jan 30;141(4):1568-1576