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, [Me3N(n)Bu][N(SO2CF3)2

The reduction of selected lanthanide cations to the zerovalent state in the room-temperature ionic liquid Me3N(n)Bu]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 = La(III), Sm(III) or Eu(III)). 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 Me3N(n)Bu]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.