Lanthanum-139 nuclear magnetic resonance spectra of lanthanum complexes

Abstract

Lanthanum-139 n.m.r. spectra are reported for a variety of lanthanum complexes and systems. The ¹³⁹La linewidths vary greatly and, as expected, an important factor appears to be the symmetry of the environment around the lanthanum. Information concerning complex formation by the La³⁺ ion is obtained from the variations in both the ¹³⁹La chemical shifts and the linewidths when a ligand is progressively added to anhydrous La[ClO₄]₃ in MeCN. Slow ligand exchange is found with the [La{P(NMe₂)₃O}₆]³⁺ ion, and with the ethylenediamine and diethylenetriamine complexes.