Electrochemical Behavior of Iron and Several Iron Complexes in Hydrophobic Room Temperature Molten Salts

Room temperature molten salts (RTMS) containing bis (trifluoromethane-sulfone) imide anions (TFSI ) are attractive electrochemical reaction media since they are not only moisturestable but also hydrophobic in addition to the various common advantages as RTMS systems, such as wide electrochemical potential window, high ionic conductivity, high thermal stability and negligible vapor pressure. Thus, these TFSI -based RTMS can be applicable to various practical uses, such as batteries, electroplating, chemical and electrochemical syntheses. We have investigated the electrochemical reaction of various lanthanides in TFSI -based RTMSs. The redox reaction of Yb / Yb was quasi-reversible probably due to their strong interaction with TFSI , whereas cyclopentadienyl ytterbium (YbCp3) showed reversible behaviors. Thus, the complex formation of a transition metal species in RTMSs affects its redox processes. In the present study, the electrochemical behavior of several iron complexes in this melt was compared with that of ligandfree iron species.