Potential-induced interfacial restructuring of a pyrrolidinium-based ionic liquid on an Au electrode: Effect of polarization of constituent ions

Potential-induced restructuring of 1-propyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)amide [C(3)mpyr][TFSA] on an Au electrode has been investigated by using surface-enhanced infrared absorption spectroscopy (SEIRAS). Cation-to-anion exchange in the double layer occurred near the potential of zero charge (pzc) whereas anion-to-cation exchange required much more negative potentials from pzc. This asymmetric behavior was clearly different from those of previously reported imidazolium-based RTILs, which highlighted the effect of charge delocalization and electronic polarization of individual ions on the stability of the multilayered interfacial structure of RTILs.