Determination of hydrophobicity scale of tetraphenylborate and its derivatives by ferrocene based three-phase electrodes

In three-phase electrodes (TPE), ferrocene (Fc) was often thought to be useless for ion transfer injection because its oxidized form has very low affinity for organic phase. Instead, lipophilic decamethylferrocene (DMFc) was employed as a better probe for the ion transfer study. However, our present results indicate that the commonly-used DMFc based TPE was not applicable for the transfer of strong hydrophobic tetraphenylborate and its derivatives (TPBs); whereas the developed Fc based TPE can meet this special requirement. Taking this advantage, we firstly evaluate the standard ion transfer energies of these TPBs and get a full knowledge of their hydrophobicity scale, which will benefit the related areas such as hydrophobic ionic liquids and lipophilic anion exchangers.