EuIII luminescence in a hygroscopic ionic liquid: effect of water and evidence for a complexation process

The spectroscopic characteristics (excitation, emission and lifetime) of Eu III dissolved in 1-methyl-3-butylimidazolium bis(trifluoromethanesulfon)imide (BumimTf2N) are reported. In a first series of experiments, the effect of the presence of water in BumimTf2N was examined. It appears that non-degassed solutions are most probably inhomogeneous, displaying large water clusters leading to an intense diffusion of the red light of an He:Ne laser. In these samples, the Eu emission spectrum is close to that observed in slightly acidic aqueous solutions. In contrast, when the samples were de