Electrochemically regulated luminescence of europium complexes with β-diketone in polyether matrices.

This study investigates the electrochemical modulation of luminescence color, , electrofluorochromism, of an Eu complex in a polyether solvent. The electrofluorochromic (EFC) reaction of the Eu complex occurred a reversible redox reaction between Eu and Eu. Initially, the intrinsically stable Eu complex showed intense red photoluminescence (PL) induced by f-f transitions. After the electrochemical reduction of Eu to Eu, broad blue PL was observed attributed to the d-f transitions in the Eu complex. This distinct blue luminescence from the Eu complex was attributed to the effective stabilization of the Eu state by the polyether solvent. The dynamic EFC reaction that changes the valence state of the Eu ion can be potentially applied to novel chemical sensors, security devices, and display devices.