Switchable phase behavior of [HBet][Tf2N]-H2O upon neodymium loading: Implications for lanthanide separations

Abstract

Task-specific ionic liquids (TSILs) present an opportunity to replace traditional organic solvents for metal dissolution or separation. To date, a thorough investigation of the physical properties of biphasic TSIL-H 2O systems and the effects of metal loading is lacking. In this work, the change in the liquid-liquid equilibrium of [HBet][Tf2N]-H 2O upon the addition of Nd(III) is investigated by cloud-point measurements. The addition of Nd(III), drops the upper critical solution temperature by over 20 C. Further investigation of the [HBet][Tf 2N]-Nd(III) system led to the formation of single crystals of [Nd2(H2O)8(μ2-Bet) 2(μ3-Bet)2][(Cl)2(Tf 2N)4] from the TSIL phase. © 2013 American Chemical Society.