- Syntheses, Structures, and Magnetic Properties of Symmetric and Dissymmetric Ester-Functionalized 3d-4f Schiff Base Complexes
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Ester-functionalized bicompartmental Schiff base ligands and their 3d-Ln complexes (3d = NiII, CuII, or ZnII and Ln = GdIII, TbIII, or DyIII) are reported. The modularity of the Schiff base structure (i.e., symmetric ester group compared with dissymmetric ester group) is illustrated to highlight the possibility offered by the ester for facile functionalization at the periphery of the ligand, in addition to its electron-withdrawing effect on the complexing core. The introduction of a chiral pool (i.e., a menthyl group) at the ester functions led to a transfer of chirality to the coordination sphere of the Ln in the solid state. Several 3d-4f complexes were found to crystallize as (NO3–)- or (OH–)-bridged compounds. Crystal structures and magnetic behaviors are reported for all of the 3d-4f complexes.
- Béreau, Virginie,Dhers, Sébastien,Costes, Jean-Pierre,Duhayon, Carine,Sutter, Jean-Pascal
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- Bi-Compartmental Schiff-Base with Peripheral Ester Functionalization: Synthesis and Magnetic Behavior of Bimetallic Zn-Ln Complexes (Ln = Dy, Tb, Gd)
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A novel ester-functionalized bi-compartmental Schiff-base ligand and its dinuclear Zn-Ln complexes [Ln = Dy (1), Tb (2), Gd (3)] are reported herein. Athough electron-withdrawing substituents at the para position of the phenol moieties do not change the coordination environment of the Ln centers in comparison with the nonfunctionalized ligand, they have a clear steric effect on the crystal packing and alter the coordination strength of the central ligand core. This is illustrated by the atypical reactivity of the bi-compartmental Schiff-base ligand towards Ln coordination and corroborated by its longer bond lengths to the rare-earth ions in comparison with the nonfunctionalized ligand. Crystal structures, magnetic behavior, and ab initio calculations for the two series of complexes are reported. A slow relaxation of the magnetization with an energy barrier of 96 K was found for Dy derivative 1 in zero field.
- Béreau, Virginie,Bolvin, Hélène,Duhayon, Carine,Sutter, Jean-Pascal
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p. 4988 - 4995
(2016/11/09)
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