Hydration of complexone complexes of lanthanide cations

Abstract

The ¹H n.m.r. spectra of some lanthanide(III) complexone complexes have been studied. The investigation showed that these complexes exist in states of fast exchange between different conformations on the surface of the metal ion. Measurements of the relaxation enhancements of water in the presence of these complexes showed a general decrease in the enhancements with increasing denticity of the ligands. This decrease was generally directly related to the hydration number of the complexes, but was also dependent on changes in electron-spin relaxation rates in different complexes.