Effects of axial ligands on the electron transfer catalyzed by manganese tatrakis(pentafluorophenyl)porphyrin in poly(γ-methyl L-glutamate) membrane
✍ Scribed by Takehisa Dewa; Mitsuru Satoh; Jiro Komiyama; Mamoru Nango; Kazuichi Tsuda
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 614 KB
- Volume
- 195
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
Poly(γ‐methyl L‐glutamate) (PMLG) membrane containing manganese tetrakis(pentafluorophenyl)porphyrinSystematic 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.