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, Me3NnBuN(SO2CF3)2

The reduction of selected lanthanide cations to the zerovalent state in the room-temperature ionic liquid Me3N(n)BuTFSI 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)BuTFSI. 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.