Enhanced EuIII ion luminescence and efficient energy transfer between lanthanide chelates within the polymeric structure in aqueous solutions

Abstract

Four new binucleating symmetric bis(4-pyridine-2,6-dicarboxylic acids) have been synthesized and luminescence enhancement of their Eu^III complexes by Y^III ions observed. The results indicate that the mechanism of enhancement is based on the formation of a polymeric structure where Eu^III ions and Y^III ions are linked together by the ligands with the consequent transfer of absorbed energy along the polymer chain through several ligands toward the Eu^III ion. The mechanism of energy transfer is probably different from the previously reported micellar co-luminescence where energy transfer occurs via the Förster dipole–dipole mechanism.