Evidence for the formation of UO2(NO3)42- in an ionic liquid by EXAFS

The complexation between uranium(VI) and nitrate ions in a hydrophobic ionic liquid (IL), namely [BMI][NO3] (BMI = 1-butyl-3-methylimidazolium(+)), is investigated by EXAFS spectroscopy. It was performed by dissolution of uranyl nitrate UO2(NO3)(2)center dot 6H(2)O or UO2(Tf2N)(2) (Tf2N = bis(trifluoromethylsulfonyl)imide (CF3SO2)(2)N-). The formation of the complex UO2(NO3)(4)(2-) is evidenced.