Lanthanide absorption spectra1/18/2024 1) In absorption the actinide bands are broader, as they are more greatly. The photophysical properties of Sm and Eu complexes are superior in non-coordinating solvents than those observed in the coordinating solvents. spectra for a given actinide according to the identity of the ligand. These changes suggest solvents influence in changing the symmetry of the field around the Ho and Er ions. In the 4f ΜΆ 4f absorption spectra, the solvents' effect is reflected on the band shape and oscillator strength of the hypersensitive transitions of ternary Ho (5 G 6 β 5 I 8) and Er (2 H 11/2 β 4 I 15/2 and 4 G 11/2 β 4 I 15/2) complexes. (III) As with transition metals, coordination number six is very common in lanthanide complexes. Luminescence occurs from a lanthanide energy level if. 1 Most importantly, this gives rise to a rich energy-level structure in the near infrared (NIR), visible (VIS), and ultraviolet (UV. The lanthanides are long known as the lighting elements. The lanthanide 4f orbitals are buried beneath the 6s, 5p, and 5d orbitals hence, spectra arising from ff transitions are narrow and insensitive to their environment, unlike transition metal (3d) spectra. Naturally, there are no analogous features for gas phase spectra. The NMR spectra of the complexes show that the complexes are stable in both coordinating and non-coordinating solvents. (II) Electronic spectra of lanthanides show very broad bands. Just as for solid state spectra, broad bands due to the transfer of charge between the metal ion and ligands are present in the spectra of lanthanide ions in solution. The shape analyses reveal that the geometry of these eight-coordinated complexes is very close to triangular dodecahedron with D 2d symmetry. The optimized structures reflect the effect of lanthanide contraction as the average bond distances decreases on going from Ho to Er. The ground state molecular structure of the ternary complexes, (Ln = Ho and Er) and their hydrated parent molecules, were determined using semi-empirical Sparkle/RM1 method. This paper presents the paramagnetic NMR, 4f-4f absorption and photoluminescence properties of the complexes of Sm, Eu, Ho and Er with hexafluoroacetylacetone (hfaa) and 1,10-phenanthroline (phen) in various coordinating and non-coordinating solvents.
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