Circularly Polarized Luminescence from Pure and Eu-Doped Trigonal TbPO·HO Nanocrystals.

In this contribution, we describe the preparation, by means of a precipitation reaction from aqueous solution at 40 °C, and the structural characterization of nanocrystalline powders of trigonal TbEuPO·HO (with = 0, 0.005, 0.01, 0.

Circularly Polarized Luminescence from New Heteroleptic Eu(III) and Tb(III) Complexes.

The complexes [Eu(bpcd)(tta)], [Eu(bpcd)(Coum)], and [Tb(bpcd)(Coum)] [tta = 2-thenoyltrifluoroacetyl-acetonate, Coum = 3-acetyl-4-hydroxy-coumarin, and bpcd = ,'-bis(2-pyridylmethyl)--1,2-diaminocyclohexane-,'-diacetate] have been synthesized and characterized from photophysical and thermodynamic points of view. The optical and chiroptical properties of these complexes, such as the total luminescence, decay curves of the Ln(III) luminescence, electronic circular dichroism, and circularly polarized luminescence, have been investigated. Interestingly, the number of coordinated solvent (methanol) molecules is sensitive to the nature of the metal ion.

Ln(III) Complexes Embedded in Biocompatible PLGA Nanoparticles as Potential Vis-to-NIR Optical Probes.

In this contribution, we present the spectroscopic study of two NIR emitting hydrophobic heteroleptic (,)-Yb(tta) and (,)-Nd(tta) complexes (with tta = 2-thenoyltrifluoroacetonate and = N,N'-bis(2-(8-hydroxyquinolinate)methylidene)-1,2-(, or ,)-cyclohexanediamine), both in methanol solution and embedded in water dispersible and biocompatible poly lactic-co-glycolic acid (PLGA) nanoparticles. Thanks to their absorption properties in a wide range of wavelengths extending from the UV up to the blue and green visible regions, the emission of these complexes can be effectively sensitized using visible radiation, which is much less harmful to tissues and skin than the UV one. The encapsulation of the two Ln(III)-based complexes in PLGA allows us to preserve their nature, making them stable in water and to test their cytotoxicity on two different cell lines, with the aim of using them in the future as potential bioimaging optical probes.

Dynamics of the Energy Transfer Process in Eu(III) Complexes Containing Polydentate Ligands Based on Pyridine, Quinoline, and Isoquinoline as Chromophoric Antennae.

In this work, we investigated from a theoretical point of view the dynamics of the energy transfer process from the ligand to Eu(III) ion for 12 isomeric species originating from six different complexes differing by nature of the ligand and the total charge. The cationic complexes present the general formula [Eu(L)(HO)] (where L = bpcd = ,'-bis(2-pyridylmethyl)--1,2-diaminocyclohexane ,'-diacetate; bQcd = ,'-bis(2-quinolinmethyl)--1,2-diaminocyclohexane ,'-diacetate; and bQcd = ,'-bis(2-isoquinolinmethyl)-1,2-diaminocyclohexane ,'-diacetate), while the neutral complexes present the Eu(L)(HO) formula (where L = PyC3A = -picolyl-,','--1,2-cyclohexylenediaminetriacetate; QC3A = -quinolyl-,','-1,2-cyclohexylenediaminetriacetate; and QC3A = -isoquinolyl-,','-1,2-cyclohexylenediaminetriacetate). Time-dependent density functional theory (TD-DFT) calculations provided the energy of the ligand excited donor states, distances between donor and acceptor orbitals involved in the energy transfer mechanism (), spin-orbit coupling matrix elements, and excited-state reorganization energies.