Higher yield of photoreduction from Eu3+ to Eu2+ with shorter wavelength irradiation

Electron Photodetachment from Aqueous Anions. 1. Quantum Yields for Generation of Hydrated Electron by 193 and 248 nm Laser Photoexcitation of Miscellaneous Inorganic Anions

“…50 ns after the end of the laser pulse. Photooxidation of water by Eu 3+ was used for actinometry at 193 nm [32]. For OH -, SO 4 2-, Cl -, and Br -, the 193 nm measurement gave QYs that were not too far from the 185 nm yields obtained by…”

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

“…However, in the region of the LMCT band of Eu(III) azide complexes the extinction coefficient of Eu 2+ is sufficiently small (e < 500) to restrict this interference. In contrast, previous studies have been carried out with EuCl 3 or Eu(ClO 4 ) 3 in aqueous or alcoholic solution [1][2][3][4]. In these cases LMCT excitation requires much shorter-wavelength irradiation.…”

“…It is assigned to a (N À 3 to Eu 3+ ) LMCT transition. LMCT excitation leads to the formation of Eu 2+ with / = 7 · 10 À4 at k irr = 333 nm.It is well known that the reduction of Eu 3+ to Eu 2+ can be achieved photochemically [1][2][3][4]. This redox photolysis is induced by LMCT (ligand-to-metal charge transfer) excitation.…”

“…Finally, the choice of water as solvent offers several advantages. In particular, any interference by organic radicals which are formed in organic solvents [1][2][3][4] is excluded.…”

Photochemistry of SmCl3 and SmBr3 in air-saturated methanol solution

“…Although a single photon in the visible region excites the f ← f transition of these ions, only luminescence is observed and no photoredox reaction can be practically induced. The direct excitation of the CT or 5d ← 4f transition bands has been found to induce the photoredox reactions of some lanthanide ions including Ce 3+ , Eu 3+ and Sm 3+ [1][2][3][4]. It is, furthermore, known that the photoreduction of Eu 3+ is taken place via an f ← f transition band by the multi-photon excitation using a dye laser [5] and a Ti:sapphire laser [6].…”