Structural Characterization of a Lanthanum Bistriflimide Complex, La(N(SO2CF3)2)3(H2O)3, and an Investigation of La, Sm, and Eu Electrochemistry in a Room-Temperature Ionic Liquid, [Me3NnBu][N(SO2CF3)2]

The reduction of selected lanthanide cations to the zerovalent state in the room-temperature ionic liquid [Me3NnBu][TFSI] is reported (where TFSI = bistriflimide, [N (SO2CF3)2]-). The lanthanide cations were introduced to the melt as the TFSI hydrate complexes [Ln(TFSI)3(H2O)3] (where Ln = LaIII, SmIII or EuIII). The lanthanum compound [La(TFSI)3(H2O)3] has been crystallographically characterized, revealing the first structurally characterized f-element TFSI complex. The lanthanide in all three complexes was shown to be reducible to the metallic state in [Me3NnBu][TFSI]. For both the Eu and Sm complexes, reduction to the metallic state was achieved via divalent species, and there was an additional observation of the electrodeposition of Eu metal.