Photolysis of aqueous europium(III) azide complexes: formation of europium(II) induced by ligand-to-metal charge transfer excitation

Europium(III) azide complexes are formed when azide is added to aqueous EuCl3. A new absorption appears at λmax = 324 nm. It is assigned to a (image to Eu3+) LMCT transition. LMCT excitation leads to the formation of Eu2+ with ϕ = 7 × 10−4 at λirr = 333 nm.