Intramolecular energy transfer and its influence on the overall quantum yields of Eu and Tb chelates with dimethyl(phenylsulfonyl)amidophosphate ligands.

Lanthanide chelates with dimethyl(phenylsulfonyl)amidophosphate (labeled as HSP) and Lewis base ligands (bpy = 2,2;-bipyridine and phen = 1,10-phenanthroline) of formula Na[Ln(SP)] (1Ln), [Ln(SP)bpy] (2Ln); [Ln(SP)phen] (3Ln) (Ln = Eu, Gd, Tb and Lu) were obtained and characterized by the X-ray, photoluminescence spectroscopy at 293 and 77 K as well as by intrinsic (Q) and overall (Q) luminescence quantum yields. These phosphors manifest a very strong emission after excitation in the UV range of the molecular singlet states (S) and two of them have very high Q values (Eu and Tb chelates of the type 2Ln and 3Ln). The dynamics of the excited states are discussed based on the intramolecular energy transfer theory, considering the dipole-dipole, the dipole-multipole and the exchange mechanisms.

Spectroscopic aspects for the Yb coordination compound with a large energy gap between the ligand and Yb excited states.

We present the experimental and theoretical results that made it possible to propose the energy transfer mechanism for a Yb complex with a large energy gap between the ligand and Yb excited states using a theoretical model and experimental data. Absorption and emission spectroscopy in the 300-4 K range is used for the study of the Yb compound with N-phosphorylated sulfonamide (Na[YbL]), which, despite the large energy gap, is characterized by high emission sensitization efficiency (η = 40%) and relatively long Yb emission lifetime (27 μs). The crystal structure of Na[YbL], radiative lifetime (930 μs), refractive index (1.

Contribution of Energy Transfer from the Singlet State to the Sensitization of Eu and Tb Luminescence by Sulfonylamidophosphates.

A series of stable lanthanide complexes Na[Ln(L) ] (Ln=La , Eu , Gd , Tb , with L=dimethyl(4-methylphenylsulfonyl)amidophosphate and dimethyl-2-naphthylsulfonylamidophosphate) were synthesized. The compounds were characterized by single-crystal X-ray diffraction, IR, absorption, and emission spectroscopy at 293 and 77 K. In contrast to the usual and well-known dominant role of the ligand triplet state in intramolecular energy transfer processes in Ln complexes, in this particular new class of Ln compounds with sulphonylamidophosphate ligands, strong experimental and detailed theoretical evidence suggest a dominant role is played by the ligand first excited singlet state.

Photodynamic effect of lanthanide derivatives of meso-tetra(N-methyl-4-pyridyl)porphine against Staphylococcus aureus.

Photodynamic therapy (PDT), used for cancer treatment, is also an alternative method for eradication of drug-resistant bacteria. This method utilizes a nontoxic light-activated dye, called a photosensitizer, and visible light to produce reactive oxygen species that lead to bacterial cell death. The purpose of this study was to investigate the bactericidal effect of PDT using lanthanide derivatives of meso-tetra(N-methyl-4-pyridyl)porphine against Staphylococcus aureus strains.

Preparation, characterization, and circularly polarized luminescence of lanthanum and europium 1,1'-binaphthyl-2,2'-diyl phosphate complexes.

Solvated tris-complexes of (R)- and (S)-1,1'-binaphthyl-2,2'-dyil phosphate with lanthanum(III) and europium(III) centers were prepared and characterized by spectroscopic methods and elemental analysis. Circularly polarized luminescence (CPL) spectra for the optically active isomers of the europium complexes are also reported.

Experimental and theoretical study of the photophysics and structures of europium cryptates incorporating 3,3'-bi-isoquinoline-2,2'-dioxide.

A detailed photophysical study of [Eu within (biqO2.2.2)(CF3SO3)](CF3SO3)2.