Electrochemical and spectroscopic studies of europium(II/III) species in a hydrophobic room-temperature ionic liquid

Abstract

The electrochemical and spectroscopic properties of divalent and trivalent europium species have been investigated in a hydrophobic room-temperature ionic liquid, 1-butyl-l-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA). The diffusion coefficients of Eu(II) and Eu(III) estimated by chronoamperometry were (3.9 ± 0.4) x 10-8 and (4.2 ± 0.7) x 10-8cm2 s-1, respectively. The diffusion of Eu(II) is affected by the coordination between Eu(II) and TFSA-. The TFSA- ligand seems to act as a weaker ligand than CH 3OH according to the splitting of the 5d levels observed from the absorption spectrum for Eu(II). The emission spectra of Eu(II) and Eu(III) were also obtained in BMPTFSA.