MIXED-LIGAND LANTHANIDE COMPLEXES .11. ABSORPTION SPECTRA AND HYPERSENSITIVITY IN THE COMPLEXES OF PR-III, ND-III, HO-III AND ER-III IN NON-AQUEOUS SOLUTIONS

摘要

Absorption spectra are reported for the mixed-ligand complexes of Pr-III, Nd-III, Ho-III, and Er-III containing ligands having nitrogen donors, in four different solvents (pyridine, DMSO, DMF and methanol). The solvents differ with respect to their donor atoms. The oscillator strengths for the hypersensitive and non-hypersensitive transitions have been determined and variations in the oscillator strengths and band shapes with respect to solvent type is rationalized in terms of ligand (solvent) structures and ligand coordination properties. Pyridine has been found most effective in promoting 4f-4f intensity and is the strongest ligand in a nephelauxetic sense among the solvents studied. (C) 1997 Elsevier Science Ltd. [References: 26]