Electrogenic and Electroneutral Pathways for Methyl Viologen-Mediated Transmembrane Oxidation-Reduction Across Dihexadecylphosphate Vesicular Membranes Научная публикация
Журнал |
Journal of Physical Chemistry (up to 1996)
ISSN: 0022-3654 |
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Вых. Данные | Год: 1994, Том: 98, Номер: 3, Страницы: 989-996 Страниц : 8 DOI: 10.1021/j100054a040 | ||||
Ключевые слова | VESICLE-BOUND VIOLOGENS; DITHIONITE; MECHANISM; DISPROPORTIONATION; SEPARATION; DIFFUSION; KINETICS; CATION | ||||
Авторы |
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Организации |
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Реферат:
Two pathways for transmembrane reduction of dihexadecylphosphate (DHP) vesicle-entrapped Co(bpy)33+ ion by photogenerated methyl viologen radical cation have been identified by quantitative evaluation of the reaction kinetics. One pathway involves electrogenic diffusion of MV+ and the other electroneutral diffusion of MV0 across the bilayer. The pathways were clearly distinguished by the self-impeding character of the electrogenic reaction, which was progressively retarded as the membrane polarization increased, and by the net stoichiometry of viologen uptake accompanying transmembrane oxidation-reduction. The first-order rate constants for transmembrane diffusion of MV+ and MV0 were estimated to be 2.7 × 10-2 s-1 and 1.1 × 103 s-1, respectively, at 23°C. The rate constant for MV+ diffusion is identical to the value previously measured by 14C-isotopic labeling methods, and other kinetic parameters were consistent with thermodynamic data obtained from measurements of Donnan equilibria. The relative contributions of the two pathways were dependent upon medium conditions; generally, the electrogenic pathway predominated during the early stages of the reaction but contributed relatively less as the transmembrane potential increased. This behavior explains the difficulties encountered in numerous earlier kinetic studies that were designed to identify the redox carrier.
Библиографическая ссылка:
Lymar S.V.
, Hurst J.K.
Electrogenic and Electroneutral Pathways for Methyl Viologen-Mediated Transmembrane Oxidation-Reduction Across Dihexadecylphosphate Vesicular Membranes
Journal of Physical Chemistry (up to 1996). 1994. V.98. N3. P.989-996. DOI: 10.1021/j100054a040 WOS Scopus РИНЦ
Electrogenic and Electroneutral Pathways for Methyl Viologen-Mediated Transmembrane Oxidation-Reduction Across Dihexadecylphosphate Vesicular Membranes
Journal of Physical Chemistry (up to 1996). 1994. V.98. N3. P.989-996. DOI: 10.1021/j100054a040 WOS Scopus РИНЦ
Даты:
Поступила в редакцию: | 6 июл. 1993 г. |
Принята к публикации: | 4 окт. 1993 г. |
Опубликована в печати: | 1 янв. 1994 г. |
Опубликована online: | 1 мая 2002 г. |
Идентификаторы БД:
Web of science | WOS:A1994MT82200040 |
Scopus | 2-s2.0-0028368257 |
РИНЦ | 26781971 |
Chemical Abstracts | 1994:48251 |
Chemical Abstracts (print) | 120:48251 |
OpenAlex | W2004194967 |