Complexation, luminescence, and energy transfer of cerium(3+) with a series of multidentate aminophosphonic acids in aqueous solution

Abstract

The luminescence of the Ce 3+ ion in aqueous solution, which results from d→f transitions, is observed to be quenched by complexation with multidentate amino carboxylic acid ligands. However, the corresponding complexes containing phosphonic acid moieties show efficient room-temperature luminescence. Luminescence spectroscopy was used to characterize Ce 3+ complexes with the following ligands: diethylenetriaminepentakis(methylphosphonic acid), ethylenediaminetetrakis(methylphosphonic acid) hexamethylenediaminetetrakis(methylphosphonic acid), and nitrilotris(methylphosphonic acid). Complex stoichiometries were determined by monitoring the emission intensity as a function of ligand concentration