The solvothermal synthesis of LnClnHO with terephthalic acid (benzene-1,4-dicarboxylic acid, HBDC) produced metal-organic frameworks (LnBDC), [Ln(BDC)(HO)], where Ln = Sm, Eu, Tb, and Dy. The materials obtained were characterized by a number of physico-chemical techniques. The influence of the ionic radius of the lanthanides on the microstructural characteristics of the Ln-MOFs was evaluated by performing Rietveld refinement.
View Article and Find Full Text PDFThe photophysical properties of two isostructural heteroligand lanthanide complexes of general formula Ln(pdtc)(phen) ( = pyrrolidinedithiocarbamate anion, = 1,10-phenanthroline), Ln = Sm (), Eu ()) were studied in solid state and dichloromethane (DCM) solution. The two lanthanide complexes were investigated by experimental techniques for structural (single-crystal X-ray diffraction analysis of , powder XRD, TG-DTA) and spectroscopic [electron paramagnetic resonance (EPR), infrared (IR), ultraviolet-visible (UV-vis), photoluminescence (PL)] characterization. DFT/TDDFT/ωB97xD and multireference SA-CASSCF/NEVPT2 calculations with perturbative spin-orbit coupling corrections were applied to construct the Jablonski energy diagrams and to discuss the excited state energy transfer mechanism with competing excited state processes and possible sensitized mechanism of metal-centered emission.
View Article and Find Full Text PDF"Core/shell" composites are based on a ferrite core coated by two layers with different properties, one of them is an isolator, SiO, and the other is a semiconductor, TiO. These composites are attracting interest because of their structure, photocatalytic activity, and magnetic properties. Nanocomposites of the "core/shell" МFeO/SiO/TiO (М = Zn(II), Co(II)) type are synthesized with a core of MFeO produced by two different methods, namely the sol-gel method (SG) using propylene oxide as a gelling agent and the hydrothermal method (HT).
View Article and Find Full Text PDFThe luminescent metal-organic complexes of rare earth metals are advanced materials with wide application potential in chemistry, biology, and medicine. The luminescence of these materials is due to a rare photophysical phenomenon called antenna effect, in which the excited ligand transmits its energy to the emitting levels of the metal. However, despite the attractive photophysical properties and the intriguing from a fundamental point of view antenna effect, the theoretical molecular design of new luminescent metal-organic complexes of rare earth metals is relatively limited.
View Article and Find Full Text PDFNew antenna ligand, 2-(phenylethynyl)-1,10-phenanthroline (PEP), and its luminescent Eu (III) complexes, Eu(PEP)Cl and Eu(PEP)(NO), are synthesized and characterized. The synthetic procedure applied is based on reacting of europium salts with ligand in hot acetonitrile solutions in molar ratio 1 to 2. The structure of the complexes is refined by X-ray diffraction based on the single crystals obtained.
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