Direct Observation of the One-Electron Reduction of Methyl Viologen Mediated by the CO2Radical Anion during TiO2Photocatalytic Reactions

Langmuir ◽  
2004 ◽  
Vol 20 (22) ◽  
pp. 9441-9444 ◽  
Author(s):  
Takashi Tachikawa ◽  
Sachiko Tojo ◽  
Mamoru Fujitsuka ◽  
Tetsuro Majima
Keyword(s):  
Direct Observation ◽  
Methyl Viologen ◽  
Electron Reduction ◽  
The One

The photochemistry of Ru(bpy)32+ in basic medium

1982 ◽  
Vol 60 (22) ◽  
pp. 2856-2858 ◽  
Author(s):  
Jin-Gou Xu ◽  
Gerald B. Porter
Keyword(s):  
Electron Transfer ◽  
Methyl Viologen ◽  
Reduction Product ◽  
Basic Medium ◽  
Electron Reduction ◽  
The One

Ru(bpy)32+ is photodecomposed in 0.3 M NaOH with [Formula: see text]. With methyl viologen also present, electron transfer quenching of the luminescence is accompanied by formation of the one electron reduction product of methyl viologen, MV+. The Ru(bpy)33+ formed in the corresponding oxidation is rapidly reduced by either OH− or MV+ to Ru(II).

Interfacial interactions and the heterogeneous one-electron reduction of methyl viologen

1987 ◽  
Vol 52 (5) ◽  
pp. 1097-1114 ◽  
Author(s):  
Michael Heyrovský ◽  
Ladislav Novotný
Keyword(s):  
Electron Transfer ◽  
Radical Cation ◽  
Electrode Surface ◽  
Methyl Viologen ◽  
Potential Range ◽  
Standard Redox Potential ◽  
Mercury Electrodes ◽  
Electron Reduction ◽  
The One ◽  
Surface Redox

The one-electron reversible electroreduction of methyl viologen to its radical cation in aqueous solutions on mercury electrodes proceeds, according to potential, concentration and time of electrolysis, in various ways. Methyl viologen is adsorbed in flat orientation at the electrode surface; it undergoes a surface redox process in π-interaction with the metal in a potential range positive by about 0.2 V of the beginning of the electroreduction. The actual reduction starts by electron transfer followed by adsorption of the radical cation and, at higher concentrations and in a narrow potential range, by crystallization at the electrode surface of a salt of the radical cation. In solution near the electrode the radical cation dimerizes and the dimer also adsorbs at the electrode. In the region of the standard redox potential and more negative the reduction proceeds by electron transfer from the electrode covered by a layer of the radical cation or of its dimer.

scholarly journals Redox and Antioxidant Modulation of Circadian Rhythms: Effects of Nitroxyl, N-Acetylcysteine and Glutathione

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2514
Author(s):  
Santiago Andrés Plano ◽  
Fernando Martín Baidanoff ◽  
Laura Lucía Trebucq ◽  
Sebastián Ángel Suarez ◽  
Fabio Doctorovich ◽  
...  
Keyword(s):  
Soluble Guanylate Cyclase ◽  
Phase Locking ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Circadian Phase ◽  
Subjective Night ◽  
Circadian Time ◽  
Electron Reduction ◽  
Locomotor Rhythms ◽  
The One

The circadian clock at the hypothalamic suprachiasmatic nucleus (SCN) entrains output rhythms to 24-h light cycles. To entrain by phase-advances, light signaling at the end of subjective night (circadian time 18, CT18) requires free radical nitric oxide (NO•) binding to soluble guanylate cyclase (sGC) heme group, activating the cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG). Phase-delays at CT14 seem to be independent of NO•, whose redox-related species were yet to be investigated. Here, the one-electron reduction of NO• nitroxyl was pharmacologically delivered by Angeli’s salt (AS) donor to assess its modulation on phase-resetting of locomotor rhythms in hamsters. Intracerebroventricular AS generated nitroxyl at the SCN, promoting phase-delays at CT14, but potentiated light-induced phase-advances at CT18. Glutathione/glutathione disulfide (GSH/GSSG) couple measured in SCN homogenates showed higher values at CT14 (i.e., more reduced) than at CT18 (oxidized). In addition, administration of antioxidants N-acetylcysteine (NAC) and GSH induced delays per se at CT14 but did not affect light-induced advances at CT18. Thus, the relative of NO• nitroxyl generates phase-delays in a reductive SCN environment, while an oxidative favors photic-advances. These data suggest that circadian phase-locking mechanisms should include redox SCN environment, generating relatives of NO•, as well as coupling with the molecular oscillator.

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