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Electron transfer catalyzed by manganese tetratolyl‐prophyrinate across poly(γ‐methyl L ‐glutamate) membrane
Author(s) -
Dewa Takehisa,
Satoh Mitsuru,
Komiyama Jiro,
Nango Mamoru,
Tsuda Kazuichi
Publication year - 1994
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1994.021950319
Subject(s) - chemistry , electron transfer , membrane , manganese , imidazole , electron transport chain , redox , catalysis , ligand (biochemistry) , buffer solution , proton , polymer chemistry , nuclear chemistry , inorganic chemistry , photochemistry , stereochemistry , organic chemistry , receptor , biochemistry , physics , quantum mechanics
A poly(γ‐methyl L ‐glutamate) (PMLG) membrane containing manganese tetratolylporphyrinate (MnTTP) was prepared in order to examine the transmembrane electron transfer in a redox system constructed as S 2 O 4 2− /membrane/Fe(CN) 6 3− . Electron transfer was observed in 0,1 M pH 7,0 imidazole (Im) buffer but not in 0,1 M pH 7,0 phosphate buffer. The apparent transfer rate increased with MnTTP content and also with the Im concentration in the buffer, indicating that electron is transferred by MnTTP, which is coupled with proton transport by Im distributed in the membrane. The transfer catalyzed by MnTTP was more effectively accelerated with Im than with 2‐methylimidazole (2‐Melm) but not at all with 1‐methylimidazole (1‐Melm). This implies that the 1‐N site on the imidazoles as the axial ligand of MnTTP is a crucial position for the mediation of electron transfer between MnTTP's. In the pH range 6,0–8,5 of Im buffer, the electron transfer rate showed a maximum at pH 7,0. This pH dependence is discussed in terms of the concentration and mobility of proton in the membrane.