| Abstract: | Poly(γ-methyl L -glutamate) (PMLG) membrane containing manganese tetrakis(pentafluorophenyl)porphyrin 1 Systematic name: Tetrakis(pentafluorophenyl)porphyrinatomanganese. (MnPFPP) has been studied for the transmembrane redox reaction between dithionite and ferricyanide in separated solutions. The effects of the ligand species, namely, OH?, Cl?, imidazole (Im), pyrazine (Pyz), triethylamine (TEA), and pyridine (Py), on the electron transfer rate in the membrane were examined. UV/VIS spectroscopy and sorption measurements confirm that these ligands are sorbed by the membrane from the external buffer solution and coordinate to MnPFPP. With the membrane containing 160 μmol · g?1 of MnPFPP, the apparent rate factor, estimated as the pseudo-first-order rate constant of the bleach of ferricyanide times membrane thickness, follows the order Im ? Cl? > Pyz > TEA, OH?, Py > 0, suggesting that Im, Cl? and Pyz are effective ligands for the electron transfer. Such a ligand-specific transfer stems from the electron-transferability of the ligands between MnPFPP's. |
