Synthesis, structures and characterisations of truly homoleptic acetonitrile Ln3+ complexes in solid state and in solution.
Total halide abstraction from LnCl3 by Ag[Al(OC(CF3)3)4]/CH3CN has been confirmed for a series of lanthanide metal ions by the structural characterization of [Ln(CH3CN)n][Al(OC(CF3)3)4]3 (n=9, Ln3+=Nd, Eu, Gd, Dy; n=8, Ln3+=Tm) complexes. Evidence for the very low coordinating ability of the [Al(OC(CF3)3)4]- anion towards Ln3+ ions is provided in the solid state (X-ray, IR and Raman spectroscopy) and in anhydrous acetonitrile solution (conductivity, EPR and NMR measurements). In the solid state homoleptic nine-coordinated acetonitrile species are characteristic for lanthanides for the beginning (Nd) and the middle (Eu, Gd, Dy) of the Ln series, with a mono-capped square antiprismatic arrangement of the N donor atoms around the metal centres; while for those from the end of the series (Tm) eight-coordinated species are representative with a square antiprismatic arrangement. In anhydrous acetonitrile solution, conductivity measurements revealed 3:1 electrolyte types for all compounds. EPR and 19F NMR line broadening measurements attest lanthanide complexes free of any coordinating [Al(OC(CF3)3)4]- anion.
Bodizs
Gabriella
G
Institut des Sciences et Ingénieries Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), BCH, CH-1015, Lausanne, Switzerland.
Raabe
Ines
I
Scopelliti
Rosario
R
Krossing
Ingo
I
Helm
Lothar
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