The 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 PDFThe tetracarbonyl complexes of transition metal chalcogenides MX(CO), where M = Fe, Co, Ni, Cu and X = S, Se, are examined by density functional theory (DFT). The MX core is cyclic with either planar or non-planar geometry. As a sulfide, it is present in natural enzymes and has a selective redox capacity.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
October 2020
Excited state energy level diagrams of coumarin-3-carboxylic acid (HCCA) chromophore, Eu(CCA)Cl(HO) (1), Eu(CCA)Cl(HO) (2) Eu(CCA)(HO) (3), Tb(CCA)Cl(HO) (4) and Tb(CCA)(NO)(HO) (5) in gas phase and polar solution have been calculated by means of DFT/TDDFT/ωB97XD methods. Based on these results, the ability of CCA to sensitize Eu(III) and Tb(III) luminescence has been examined. The competitive excited state processes in the complexes - fluorescence, intersystem crossing (ISC) and phosphorescence, were analyzed depending on the environment, number of the ligands, Ln(III) ion type (Eu and Tb) and counteranion (Cl and NO).
View Article and Find Full Text PDFFully atomistic molecular dynamics simulations were performed on liquid n-pentane, n-hexane, and n-heptane to derive an atomistic model for middle-chain-length alkanes. All simulations were based on existing molecular-mechanical parameters for alkanes. The computational protocol was optimized, for example, in terms of thermo- and barostat, to reproduce properly the properties of the liquids.
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