Dinuclear Lanthanide(III) Complexes by Metal-Ion-Assisted Hydration of Di-2-pyridyl Ketone Azine

Abstract

The initial employment of di-2-pyridyl ketone azine in 4f metal chemistry has led to a unique ligand transformation; the resulting anionic ligand is able to bridge two Ln(III) ions, affording neutral and cationic dinuclear complexes with interesting properties.

Dinuclear, tetrakis(acetato)-bridged lanthanide(III) complexes from the use of 2-acetylpyridine hydrazone

“…Upon cooling, the χ M T product decreases slightly in the range 300-60 K, followed by a rapid decrease on lowering the temperarure from 60 to 5.0 K to reach a final value of 17.5 cm 3 K mol -1 . This thermal behavior is associated with the depopulation of the Dy III Stark sublevels and possibly with the presence of weak antiferromagnetic Dy III •••Dy III exchange interactions within the molecule [2,9,19]. The latter was further established by a Curie-Weiss analysis of the "high-temperature" (30-300 K) magnetic susceptibility data (Fig.…”

“…In the areas of Single-Molecule Magnets (SMMs) and Single-Ion Magnets (SIMs), for example, molecular Ln 2 SMMs/SIMs are valuable model systems which can be used to answer fundamental questions concerning single-ion relaxation versus slow relaxation arising from the molecule as an entity [1,[3][4][5]. In addition, Ln 2 complexes play a key role in other scientific fields/areas, such as quantum computing [6], magnetic refrigeration [7], optics [8] and catalysis [9].…”

Using the Singly Deprotonated Triethanolamine to Prepare Dinuclear Lanthanide(III) Complexes: Synthesis, Structural Characterization and Magnetic Studies

“…neutral capping organic ligands, which terminate oligomerization or polymerization by blocking two or three coordination sites per Ln III center [23]. Another method is the simultaneous employment of capping bidentate nitrato groups (nitrato ligands have little tendency for bridging in Ln III chemistry) and neutral or anionic organic ligands that can, in principle, bridge only two metal centers; in addition to the bridging functionality, the ligands should preferably possess "chelating" parts to satisfy the demand for high coordination numbers at the Ln III centers [24][25][26]. Thus, the choice of the primary organic ligands is crucial for the synthesis of Ln III 2 complexes.…”

“…With all the above in mind and given the recently initiated interest of our groups in Ln III 2 complexes with interesting magnetic and/or luminescence properties [23,[25][26][27], we report here the synthesis, structures and magnetic properties of new such complexes bearing the monoanion of tris(2-hydroxyethyl)amine (the empirical name is triethanolamine, abbreviated hereafter as teaH 3 , Scheme 1). This ligand is very popular in 3d-and mixed 3d/4f-metal cluster chemistry (representative 3d/4f-metal compounds based on anionic forms of teaH 3 are described in refs [28][29][30][31]), but with limited used in homometallic Ln III and neutral or anionic organic ligands that can, in principle, bridge only two metal centers; in addition to the bridging functionality, the ligands should preferably possess "chelating" parts to satisfy the demand for high coordination numbers at the Ln III centers [24][25][26]. Thus, the choice of the primary organic ligands is crucial for the synthesis of Ln III 2 complexes.…”

“…Thus, the choice of the primary organic ligands is crucial for the synthesis of Ln III 2 complexes. With all the above in mind and given the recently initiated interest of our groups in Ln III 2 complexes with interesting magnetic and/or luminescence properties [23,[25][26][27], we report here the synthesis, structures and magnetic properties of new such complexes bearing the monoanion of tris(2-hydroxyethyl)amine (the empirical name is triethanolamine, abbreviated hereafter as teaH3, Scheme 1). This ligand is very popular in 3d-and mixed 3d/4f-metal cluster chemistry (representative 3d/4f-metal compounds based on anionic forms of teaH3 are described in refs [28][29][30][31]), but with limited used in homometallic Ln III [37][38][39].…”