Combining the Best of Two Chelating Titans: A Hydroxypyridinone‐Decorated Macrocyclic Ligand for Efficient and Concomitant Complexation and Sensitized Luminescence of f‐Elements

• DOI: 10.1002/cplu.202100083
• Publication Date: 2021-03-18T05:06:07Z
• Authors: Leticia Arnedo‐Sa...; Kurt F. Smith; Gauthier J.‐P. De...; Korey P. Carter; Liane M. Moreau; Julian A. Rees; Toni Tratnjek; Corwin H. Booth; Rebecca J. Abergel
• Keywords: Cyclen; Chemical Stability; Coordination complex; Coordination sphere; Macrocyclic ligand; Cryptand

Abstract An ideal chelator for f‐elements features rapid kinetics of complexation, high thermodynamic stability, and slow dissociation. Here we present the facile synthesis a macrocyclic ligand bearing four 1‐hydroxy‐2‐pyridinone units linked to cyclen scaffold that rapidly forms thermodynamically stable complexes with lanthanides (Sm 3+ , Eu Tb Dy ) representative late actinide (Cm in aqueous media concurrently sensitizes them. Extended X‐ray absorption fine structure (EXAFS) spectroscopy revealed an increase Ln/An−O bond lengths following trend Cm>Eu>Tb EXAFS data were compatible time‐resolved luminescence studies, which indicated one two water molecules inner metal coordination sphere Eu(III) Cm(III) complex. Spectrofluorimetric competition titrations against DTPA confirmed stability DOTHOPO complexes, pM values between 19.9(1) 21.9(2).