Green luminescence of the europium chloride:dimethylformamide charge-transfer complex

A wide emission band located at ∼530 nm was observed upon UV irradiation of the dimethylformamide solution of EuCl3 with excess of the chloride anions in the solution. Intensity of the emission band was found to be several times higher as compared with the emission lines at 590 and 612 nm originating from the trivalent europium ions. The origin of the green emission band is assigned to the divalent europium ions formed as a result of electron transfer from the dimethylformamide (DMFA)/Cl− environment to the Eu3+ cations.