Tetraphenylantimony(V)-assisted transfer of hydroxide and fluoride anions across the 1,6-dichlorohexane | water interface

The ion-transfer reaction at the 1,6-dichlorohexane (DCH) | water (W) interface in the presence of an organometallic cation, tetraphenylantimony (TPhSb + ), in DCH was studied voltammetrically. When TPhSb + salt with [(C 4 F 9 SO 2 ) 2 N] - ion was added to the DCH-phase and the W-phase was buffered at pH < 6, a reversible cyclic voltammogram due to the simple transfer of TPhSb + ion across the DCH | W interface was observed within the polarizable potential window. When the W-phase was buffered at pH > 7, the midpoint potential shifted to more positive potentials with increasing pH. The voltammogram could be attributed to the transfer of the OH - ion assisted by the formation of TPhSbOH, which is stable in DCH. Also, a 7reversible voltammogram due to the TPhSb + -assisted transfer of F - ion was observed at the TPhSb + (DCH) | F - (W, unbuffered) interfacial system. The same results were achieved when TPhSb[(C 4 F 9 SO 2 ) 2 N] in DCH was replaced by TPhSbOH or TPhSbF, indicating the applicability of the TPhSb + and TPhSbOH (DCH) | OH - (W) interfacial system to a pH sensor for alkaline solution and that of the TPhSb + and TPhSbF (DCH) | F - (W) interface to a F - ion sensor.