Seven-Coordinate Tb Complexes with 90% Quantum Yields: High-Performance Examples of Combined Singlet- and Triplet-to-Tb Energy-Transfer Pathways.

Seven-coordinate, pentagonal-bipyramidal (PBP) complexes [Ln(bbpen)Cl] and [Ln(bbppn)Cl], in which Ln = Tb (products and ), Eu ( and ), and Gd ( and ), with bbpen = ,'-bis(2-oxidobenzyl)-,'-bis(pyridin-2-ylmethyl)ethylenediamine and bbppn = ,'-bis(2-oxidobenzyl)-,'-bis(pyridin-2-ylmethyl)-1,2-propanediamine, were synthesized and characterized by single-crystal X-ray diffraction analysis, alternating-current magnetic susceptibility measurements, and photoluminescence (steady-state and time-resolved) spectroscopy. Under a static magnetic field of 0.1 T, the Tb complexes and revealed single-ion-magnet behavior.

Promoting a Significant Increase in the Photoluminescence Quantum Yield of Terbium(III) Complexes by Ligand Modification.

Two discrete mononuclear complexes, [Tb(bbpen)(NO)] () and [Tb(bbppn)(NO)] (), for which = -bis(2-hydroxybenzyl)--bis(pyridin-2-ylmethyl)ethylenediamine and = bis(2-hydroxylbenzyl)-bis(pyridin-2-ylmethyl)-1,2-propanediamine, were synthesized and characterized by FTIR, Raman, and photoluminescence (PL, steady-state and time-resolved modes) spectroscopy. The attachment of a methyl group to the ethylenediamine portion of the ligand backbone differentiates from and acts as a determining feature to both the structural and optical properties of the former. The single-crystal X-ray structure of is described here for the first time, while that of complex has been redetermined in the monoclinic 2 space group in light of new diffraction data.

Crystal structures of binuclear complexes of gadolinium(III) and dysprosium(III) with oxalate bridges and chelating ,'-bis-(2-oxido-benz-yl)-,'-bis-(pyridin-2-ylmeth-yl)ethyl-enedi-amine (bbpen).

The reaction between mononuclear [(bbpen)Cl] [ = Gd or Dy; Hbbpen = ,'-bis-(2-hy-droxy-benz-yl)-,'-bis-(pyridin-2-ylmeth-yl)ethyl-enedi-amine, CHNO] and potassium oxalate monohydrate in water/methanol produced the solvated centrosymmetric isostructural binuclear (μ-oxalato)bis-{[,'-bis-(2-oxidobenzyl-κ)-,'-bis-(pyridin-2-ylmethyl-κ)ethyl-enedi-amine-κ ,']dilanthanide(III)}-methanol-water (1/4/4) complexes, [ (CHNO)(CO)]·4CHOH·4HO, with lanthanide(III) = gadolinium(III) ( = Gd) and dysprosium(III) ( = Dy), in high yields ( 70%) directly from the reaction mixtures. In both complexes, the lanthanide ion is eight-coordinate and adopts a distorted square-anti-prismatic coordination environment. The triclinic ( ) unit cell contains one dimeric unit together with four water and four methanol mol-ecules; in the final structural model, two of each type of solvating mol-ecule refine well.