Cu-Ln complexes involving non-symmetrical ligands able to introduce asymmetric centres in the vicinity of Ln ions. (15th September 2022)

• Record Type: Journal Article
• Authors: Zohra Chiboub Fellah, Fatima; Duhayon, Carine; Mallet-Ladeira, Sonia; Vendier, Laure; Costes, Jean-Pierre
• Is Part Of: Polyhedron. Volume 224(2022)
• Publication Date: 2022-09-15
• Subjects: Copper -- Lanthanides -- Ligand design -- Structural determination -- Magnetic properties -- Stereogenic centre; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2022.116015
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Reaction of the present complex with Gd III ions yields a tetranuclear [Cu-Gd]2 entity but does not allow to keep the stereogenic Cu centre present in the starting Cu II complex. Abstract: The present work confirms the difficulty to prepare main ligands able to coordinate 3d and 4f ions and to bring asymmetric centres in the vicinity of the Ln ions. Although our two first examples were not realized with pure enantiomers, we have shown that introduction of 3d ions in these ligands was possible but problems arise with the complexation of the Ln III ions. Due to these difficulties, we used an original reaction pathway. A trianionic ligand possessing one amide, one imine, two phenol functions reacts with Cu II ions to yield an anionic complex that crystallizes in a non-centrosymmetric space group, due to the presence of a stereogenic Cu II centre. Further reaction with Ln III ions in presence of ancillary ligands yields tetranuclear complexes made of two LCuGd units in a head-to-tail arrangement. Ferromagnetic Cu-Ln interactions, resulting from an alternate distribution of the Cu II and Ln III ions, are the only ones to be active. But this tetranuclear complex is no more chiral, the conformation change of the ligand diamino chain around one Cu II ion yielding two Cu II ions of opposite chiralities.