A Coordination Chemistry Approach to Fine‐Tune the Physicochemical Parameters of Lanthanide Complexes Relevant to Medical Applications. Issue 13 (6th February 2018)

• Record Type: Journal Article
• Authors: Le Fur, Mariane; Molnár, Enikő; Beyler, Maryline; Kálmán, Ferenc K.; Fougère, Olivier; Esteban‐Gómez, David; Rousseaux, Olivier; Tripier, Raphaël; Tircsó, Gyula; Platas‐Iglesias, Carlos
• Is Part Of: Chemistry. Volume 24:Issue 13(2018)
• Page Start: 3127
• Page End: 3131
• Publication Date: 2018-02-06
• Subjects: lanthanides -- macrocycles -- MRI -- NMR spectroscopy -- water exchange; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201705528
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The geometric features of two pyclen‐based ligands possessing identical donor atoms but different site organization have a profound impact in their complexation properties toward lanthanide ions. The ligand containing two acetate groups and a picolinate arm arranged in a symmetrical fashion (L1 ) forms a Gd 3+ complex being two orders of magnitude less stable than its dissymmetric analogue GdL2 . Besides, GdL1 experiences a much faster dissociation following the acid‐catalyzed mechanism than GdL2 . On the contrary, GdL1 exhibits a lower exchange rate of the coordinated water molecule compared to GdL2 . These very different properties are related to different strengths of the Gd‐ligand bonds associated to steric effects, which hinder the coordination of a water molecule in GdL2 and the binding of acetate groups in GdL1 . Abstract : More than meets the eye : An apparently innocent change in the arrangement of the ligand donor atoms around the central Ln 3+ ion has profound consequences in the thermodynamic stability and dissociation and water exchange kinetics of the complexes.