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Combining the Best of Two Chelating Titans: A Hydroxypyridinone‐Decorated Macrocyclic Ligand for Efficient and Concomitant Complexation and Sensitized Luminescence of f‐Elements
Author(s) -
ArnedoSanchez Leticia,
Smith Kurt F.,
Deblonde Gauthier J.P.,
Carter Korey P.,
Moreau Liane M.,
Rees Julian A.,
Tratnjek Toni,
Booth Corwin H.,
Abergel Rebecca J.
Publication year - 2021
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.202100083
Subject(s) - cyclen , luminescence , chemistry , aqueous solution , lanthanide , molecule , ligand (biochemistry) , extended x ray absorption fine structure , cryptand , kinetics , chelation , coordination sphere , dissociation (chemistry) , coordination complex , titration , macrocyclic ligand , chemical stability , actinide , inorganic chemistry , absorption spectroscopy , metal , stereochemistry , materials science , organic chemistry , ion , biochemistry , receptor , optoelectronics , physics , quantum mechanics
An ideal chelator for f‐elements features rapid kinetics of complexation, high thermodynamic stability, and slow kinetics of dissociation. Here we present the facile synthesis of a macrocyclic ligand bearing four 1‐hydroxy‐2‐pyridinone units linked to a cyclen scaffold that rapidly forms thermodynamically stable complexes with lanthanides (Sm 3+ , Eu 3+ , Tb 3+ , Dy 3+ ) and a representative late actinide (Cm 3+ ) in aqueous media and concurrently sensitizes them. Extended X‐ray absorption fine structure (EXAFS) spectroscopy revealed an increase in the Ln/An−O bond lengths following the trend Cm>Eu>Tb and EXAFS data were compatible with time‐resolved luminescence studies, which indicated one to two water molecules in the inner metal coordination sphere of Eu(III) and two water molecules for the Cm(III) complex. Spectrofluorimetric ligand competition titrations against DTPA confirmed the high thermodynamic stability of DOTHOPO complexes, with pM values between 19.9(1) and 21.9(2).