This study presents the electrochemical properties of room-temperature ionic liquids (RTILs) at a variety of liquid-liquid interfaces. The RTILs used here consist of 1-alkyl-3-methylimidazolium (C(n)mim, n = 6, 8, 10, 12) cations with bis(perfluoromethylsulfonyl)imide (BMSI) and bis(perfluoroethylsulfonyl)imide (BETI) anions. Ion transfer across the polarizable 1,2-dichloroethane/water and the neat RTIL/water interfaces were examined. The ion-transfer experiments suggested that the RTILs made with Cnmim and BMSI or BETI are moderately hydrophobic with polarizable potential windows as large as 274 mV for C(12)mimBETI in 1,2-dichloroethane and 137 mV for the neat C(12)mimBETI/water interface. In addition, the effect of the junction potential at the aqueous Ag/AgCl reference electrode/RTIL interface was studied using the oxidation/reduction of ferrocene and decamethylferrocene. The junction potential at the reference electrode was found to decrease as a function of the cation chain length for both anions studied. The Delta(o)(w)G(tr) of transfer found for all the systems studied was similar to 3 kJ/ mol per CH2 group of the cation. (c) 2005 The Electrochemical Society. All rights reserved.