Monometallic and bimetallic europium(III) and terbium(III) complexes: Synthesis and luminescent properties

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

“…It is observed that the bands of the free aphz are red-shifted when bound in the complexes, due to coordination. The f-f transitions of the Ln III ions are too weak to be observed; moreover, no photoluminescent behaviour was detected for the three complexes in the solid state at room temperature, suggesting that aphz can not act as "antenna" to enhance the emission of Eu III , Tb III and Dy III in the visible region [20].…”

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

“…In the same molecular architecture, the substitution of Ising-like spins, such as lanthanides, can offer a weak exchange coupling to study their possible implementation as qugates. Dinuclear lanthanide complexes with bpm as the bridge were reported before, but only a few studies describe their magnetic properties [ 22 – 30 ]. In this work we report the synthesis, characterization and single-crystal structure determination of five examples of homo-dinuclear complexes of tris-β-diketonate adducts of Gd(III), Tb(III) [ 30 ], Dy(III), Ho(III) and Er(III) with a bpm bridging ligand.…”

“…Dinuclear lanthanide complexes with bpm as the bridge were reported before, but only a few studies describe their magnetic properties [ 22 – 30 ]. In this work we report the synthesis, characterization and single-crystal structure determination of five examples of homo-dinuclear complexes of tris-β-diketonate adducts of Gd(III), Tb(III) [ 30 ], Dy(III), Ho(III) and Er(III) with a bpm bridging ligand. We employed 2,2’,6,6’-tetramethyl-2,4-heptanedionate (tmhd) ligands as peripheric ligands, providing overall charge-neutral compounds.…”

From Mono- to Polynuclear Coordination Complexes with a 2,2′-Bipyrimidine-4,4′-dicarboxylate Ligand

“…The 2,2′-bipyrimidine ( bpym ) core is a versatile motif in coordination chemistry and has been used for a long time as a bridging ligand for the synthesis of homodinuclear, heterodinuclear, or coordination networks − with rich spectroscopic, − electronic, and magnetic properties. − In particular, heterodinuclear d – f complexes of the molecular formula [L 2 Pt­(μ- bpym )­Ln­(hfac) 3 ] (Ln = Yb, Nd, or Er) have been designed by Ward and collaborators, showing a short intermetallic distance across the bipyrimidine bridge (6.3 Å), which leads to an efficient sensitization of the Ln near-infrared (NIR) luminescence by the d -block unit, due to an energy transfer from the 3 MLCT state to the lanthanide (Ln) excited state. Similarly, Seitz and co-workers used the bipyrimidine motif to construct highly stable homo- and heterodinuclear cryptate-based Ln complexes .…”

“…Depending on the respective orientation of the carboxylate functions, the bpd 2– unit can bridge metal centers in various chelating modes [bidentate, tridentate, and tetradentate (Figure )], providing an interesting interplay between soft and hard complexing sites . It provides the combined advantages of the tetradentate coordination of 2,2′-bipyrimidine-4,4′-dicarboxylic acid ( bpdc ) , together with the Janus-type coordination of pyrimidine , and bipyrimidine ( bpym ). − …”