Biomimetic Charge Transfer Reactions at the Aqueous/Organic Solution Interface or through Artificial Membrane

Some biomimetic reactions observed with the aid of aqueous/organic, W/O, two phases or liquid membrane, LM, systems were introduced. The reactions introduced were mostly those reported by the group of present authors as follows; (1) Transformations of porphyrin iron(III) complex, Fe(P), and a-tocopherol, a-TOH, derivatives in 0 contacted with W. (2) The oxidation of Fe(P) in O with an oxidant in W, a-TOH in 0 with nitric oxide in W or hydroquinone in O with oxygen in W, and the reduction of quinone in O with beta-nicotinamide adenine dinucleotide in W. (3) A respiration mimetic reaction accompanied by the selective ion transfer at the W/O interface. (4) Biomimetic charge transport reactions observed by LM systems such as the oscillation of membrane current. (5) A new type of membrane transport reaction realized in the presence of an applied electrical potential gradient parallel to the W/membrane interface. The processes of above-described reactions were elucidated based on the voltammetric methods and concepts taking into account the properties common to both artificial LMs and biomembranes. A method proposed by present authors for the elucidation of the membrane transport process was also introduced. (C) The Electrochemical Society of Japan, All rights reserved.