Figure 5.
(A) Co K-edge and (B) Ni K-edge XANES experimental spectra of solid Co(Tf2N)2 and Ni(Tf2N)2, respectively, compared with the 0.1 mol L–1 solutions in ILs carrying the [Tf2N]− anion with different organic cations, namely, [C4mim]+ (black lines), [C8(mim)2]2+ (red lines), [choline]+ (blue lines), and [BTMA]+ (green lines).