Spectroscopic and electrochemical analyses for dysprosium complexes in potassium bis(trifluoromethylsulfonyl)amide melts

Matsumiya, Masahiko*; Nomizu, Daiki*; Tsuchida, Yusuke*; Sasaki, Yuji  

The coordination states of multivalent dysprosium complexes of potassium bis(trifluoromethylsulfonyl) amide (K[NTf]) were investigated by Raman spectroscopy. The solvation number, n, of the dysprosium complexes was determined to be 4.12 for Dy(II) and 5.09 for Dy(III). Electrochemical analysis revealed that the reduction peak of [Dy-III(NTf)(5)](2-) at approximately +0.81 V at 483 K is based on an electrodeposition reaction from [Dy-III(NTf)(5)](2-) to Dy(0). The nucleation behavior of [Dy-III(NTf)(5)](2-) was evaluated using chronoamperometry. The results indicated that the nucleation mechanism of Dy nuclei changed from instantaneous to progressive nucleation when the overpotential became more negative than the deposition potential of Dy(0). The electrodeposits were identified as mostly the metallic state by X-ray photoelectron spectroscopy.