scholarly journals Ultralong π-Conjugated Bis(terpyridine)metal Polymer Wires Covalently Bound to a Carbon Electrode: Fast Redox Conduction and Redox Diode Characteristics

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4267
Author(s):  
Kuo-Hui Wu ◽  
Ryota Sakamoto ◽  
Hiroaki Maeda ◽  
Eunice Jia Han Phua ◽  
Hiroshi Nishihara
Keyword(s):  
Metal Complex ◽  
Electrochemical Method ◽  
Redox Reactions ◽  
Cyclic Voltammograms ◽  
Wire Arrays ◽  
Reversible Redox ◽  
Complex Linear ◽  
Complex Polymer ◽  
Metal Polymer ◽  
Hclo4 Solution

We developed an efficient and convenient electrochemical method to synthesize π-conjugated redox metal-complex linear polymer wires composed of azobenzene-bridged bis(terpyridine)metal (2-M, M = Fe, Ru) units covalently immobilized on glassy carbon (GC). Polymerization proceeds by electrochemical oxidation of bis(4′-(4-anilino)-2,2′:6′,2″-terpyridine)metal (1-M) in a water–acetonitrile–HClO4 solution, affording ultralong wires up to 7400 mers (corresponding to ca. 15 μm). Both 2-Fe and 2-Ru undergo reversible redox reactions, and their redox behaviors indicate remarkably fast redox conduction. Anisotropic hetero-metal-complex polymer wires with Fe and Ru centers are constructed via stepwise electropolymerization. The cyclic voltammograms of two hetero-metal-complex polymer wires, GC/[2-Fe]–[2-Ru] (3) and GC/[2-Ru]–[2-Fe] (4), show irreversible redox reactions with opposite electron transfer characteristics, indicating redox diodelike behavior. In short, the present electrochemical method is useful to synthesize polymer wire arrays and to integrate functional molecules on carbon.

Thermo-chemical water splitting: Selection of priority reversible redox reactions by multi-attribute decision making

2021 ◽  
Vol 170 ◽  
pp. 800-810
Author(s):  
Yimin Deng ◽  
Raf Dewil ◽  
Lise Appels ◽  
Shuo Li ◽  
Jan Baeyens ◽  
...  
Keyword(s):  
Decision Making ◽  
Water Splitting ◽  
Redox Reactions ◽  
Reversible Redox ◽  
Multi Attribute Decision Making ◽  
Chemical Water ◽  
Selection Of

Reversible Redox Reactions in an Extended Polyoxometalate Framework Solid

2008 ◽  
Vol 47 (36) ◽  
pp. 6881-6884 ◽  
Author(s):  
Chris Ritchie ◽  
Carsten Streb ◽  
Johannes Thiel ◽  
Scott G. Mitchell ◽  
Haralampos N. Miras ◽  
...  
Keyword(s):  
Redox Reactions ◽  
Reversible Redox

scholarly journals Reversible signal regulation system of 19F NMR by redox reactions using a metal complex as a switching module

2009 ◽  
Vol 17 (11) ◽  
pp. 3818-3823 ◽  
Author(s):  
Kazuo Tanaka ◽  
Narufumi Kitamura ◽  
Yuichi Takahashi ◽  
Yoshiki Chujo
Keyword(s):  
Metal Complex ◽  
Redox Reactions ◽  
19F Nmr ◽  
Regulation System ◽  
Signal Regulation

scholarly journals Electron Inventory of the Iron-Sulfur Scaffold Complex HypCD Essential in [NiFe]-Hydrogenase Cofactor Assembly

2021 ◽  
Author(s):  
Sven T. Stripp ◽  
Jonathan Oltmanns ◽  
Christina S. Müller ◽  
David Ehrenberg ◽  
Ramona Schlesinger ◽  
...  
Keyword(s):  
Redox Reactions ◽  
Redox Activity ◽  
Construction Site ◽  
Iron Ion ◽  
Paramagnetic Resonance ◽  
Iron Sulfur ◽  
Reducing Conditions ◽  
Reversible Redox ◽  
Electron Paramagnetic ◽  
Redox Conversion

The [4Fe-4S] cluster containing scaffold complex HypCD is the central construction site for the assembly of the [Fe](CN)2CO cofactor precursor of [NiFe]-hydrogenase. While the importance of the HypCD complex is well established, not much is known about the mechanism by which the CN– and CO ligands are transferred and attached to the iron ion. We developed an efficient protocol for the production and isolation of the functional HypCD complex that facilitated detailed spectroscopic investigations. The results obtained by UV/Vis-, electron paramagnetic Resonance (EPR)-, Resonance Raman-, Fourier-transform infrared (FTIR), and Mössbauer spectroscopy provide comprehensive evidence for an electron inventory fit to drive multi-electron redox reactions. We demonstrate the redox activity of the HypCD complex reporting the interconversion of the [4Fe-4S]2+/+ couple. Additionally, we observed a reversible redox conversion between the [4Fe-4S]2+ and a [3Fe-4S]+ cluster. MicroScale thermophoresis indicated preferable binding between the HypCD complex and its interaction partner HypEF under reducing conditions. Together, these results suggest a redox cascade involving the [4Fe-4S] cluster and a conserved disulfide bond of HypD that may facilitate the synthesis of the [Fe](CN)2CO cofactor precursor on the HypCD scaffold complex.

scholarly journals Electrochemical synthesis of poly(2-methyl aniline): electrochemical and spectroscopic characterization

2001 ◽  
Vol 66 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Aleksandra Buzarovska ◽  
Irena Arsova ◽  
Ljubomir Arsov
Keyword(s):  
Raman Spectroscopy ◽  
Cyclic Voltammetry ◽  
Redox Reactions ◽  
Electrochemical Polymerization ◽  
Spectroscopic Characterization ◽  
Potential Range ◽  
Cyclic Voltammograms ◽  
Impedance Measurements ◽  
Order Of Magnitude ◽  
Poly Aniline

Poly(2-methyl aniline) or poly(ortho-toluidine), as ring substituted derivative of aniline, has been synthesized electrochemically in various concentrations of H2SO4 and HCl, and then characterized by cyclic voltammetry, as well as by impedance and Raman spectroscopy. The cyclic voltammograms of poly(o-toluidine) and poly(aniline) show that the electrochemical polymerization of these two polymers proceeds by almost identical mechanisms. The Raman spectroscopical measurements suggest that the redox reactions of poly(aniline) and poly(o-toluidine) are similar in the potential range between -0.2 and 0.7V vs. SCE. The impedance measurements showed that the conductivity of poly(o-toluidine) is an order of magnitude lower than that of the corresponding poly(aniline) form.

A Stable Thin Film from Soluble Single-Walled Carbon Nanotubes on ITO

2011 ◽  
Vol 287-290 ◽  
pp. 2443-2446
Author(s):  
Su Min Wang ◽  
Qi Guan Wang ◽  
Jian Ping Li ◽  
Hiroshi Moriyama ◽  
Wei Xing Chen
Keyword(s):  
Carbon Nanotubes ◽  
Redox Reactions ◽  
Conductive Polymer ◽  
Stable State ◽  
Single Walled Carbon Nanotubes ◽  
Organic Media ◽  
Covalent Bonds ◽  
Single Walled Carbon ◽  
Reversible Redox ◽  
Walled Carbon Nanotubes

Thin films of single-walled carbon nanotubes (SWNTs) attached to an ITO surface (SAM–ITO) self-assembled in advance from 3-aminopropyltrimethoxysilane through amide covalent bonds were prepared. The SWNTs were safely obtained via a two-step process assisted by microwave radiation, which were soluble in aqueous and organic media. However, the CV behavior of SAM–ITO in acidic aqueous systems showed unexpected oxidation signals due to redox reactions involving the defects and sidewalls of soluble functionalized SWNTs. It was found that, after a conductive polymer of polyaniline was chemically incorporated onto the surface of the SWNTs by using electropolymerization method, the CV data showed a single reversible redox couple, which indicated a more stable state.

scholarly journals Pseudocapacitive behavior of the Fe2O3 anode and its contribution to high reversible capacity in lithium ion batteries

Nanoscale ◽  
2018 ◽  
Vol 10 (37) ◽  
pp. 18010-18018 ◽  
Author(s):  
Yimo Xiang ◽  
Zhigao Yang ◽  
Shengping Wang ◽  
Md. Shahriar A. Hossain ◽  
Jingxian Yu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Lithium Ion Batteries ◽  
Redox Reactions ◽  
Lithium Ion ◽  
Transition Metal Oxide ◽  
Reversible Capacity ◽  
High Reversible Capacity ◽  
Reversible Redox ◽  
Pseudocapacitive Behavior

Pseudocapacitance, which is the storage of charge based on continuous and fast reversible redox reactions at the surface of the electrodes, is commonly observed in transition metal oxide based LIB anodes.

Metal–polymer nanocomposites based on Ni nanoparticles and polythiophene obtained by electrochemical method

2015 ◽  
Vol 352 ◽  
pp. 95-102 ◽  
Author(s):  
Petronela Pascariu ◽  
Anton Airinei ◽  
Mircea Grigoras ◽  
Loredana Vacareanu ◽  
Felicia Iacomi
Keyword(s):  
Polymer Nanocomposites ◽  
Electrochemical Method ◽  
Ni Nanoparticles ◽  
Metal Polymer

A Critical Evaluation of the Redox Properties of Uranium, Neptunium and Plutonium Ions in Acidic Aqueous Solutions

1999 ◽  
Vol 71 (9) ◽  
pp. 1771-1807 ◽  
Author(s):  
Sorin Kihara ◽  
Zenko Yoshida ◽  
Hisao Aoyagi ◽  
Kohji Maeda ◽  
Osamu Shirai ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Redox Reactions ◽  
Critical Evaluation ◽  
Redox Properties ◽  
Redox Processes ◽  
Redox Potentials ◽  
Electrode Processes ◽  
Reversible Redox ◽  
Reduction Mechanisms ◽  
Current Potential

Standard redox potentials, E0s, and redox processes of U, Np and Pu ions in acidic aqueous solutions are reviewed and evaluated critically. The E0sof reversible redox processes, MO22+/MO2+ and M4+/M3+ (M: U, Np or Pu) adopted are those proposed mainly by Riglet et al. on the basis of the precise correction of formal potentials, E0's, according to the improved theoretical approach to estimate the activity coefficient. Electrode processes of the U, Np and Pu ions are discussed in terms of current-potential curves, measured so far by polarography, voltammetry or flow coulometry. Special attention is payed to the irreversible MO2+/M4+ reactions. Disproportionation reactions of MO2+ are also discussed. New substances are introduced as intermediates during reductions of MO2+ to M4+ or disproportionations of MO2+.CONTENTSIntroductionStandard redox potentials for uranium, neptunium and plutonium ions in acidic aqueous solutions2.1 Evaluation of E0 from E0' determined by electrochemical measurements2.2 Temperature dependence of E0Redox reactions of uranium, neptunium and plutonium in acidic aqueous solutions investigated by polarography or voltammetry3.1 Uranium3.2 Neptunium3.3 Plutonium3.4 Disproportionation of NpO2+, PuO2+, Np4+ and Pu4+3.5 Reduction of MO2+ and reduction intermediatesRedox reactions of uranium, neptunium and plutonium in acidic aqueous solutions investigated by flow coulometry4.1 Electrode processes of the uranium, neptunium and plutonium ions investigated by flow coulometry at the column electrode at the column electrode4.2 Disproportionation of MO2+ during the electrolysis by flow coulometry4.3 Reduction mechanisms of MO2+ (M = Np or Pu) and reduction intermediates investigated by flow coulometryConclusionsList of abbreviationsAppendixReferences

Quinone/hydroquinone redox couple as a source of enormous capacitance of activated carbon electrodes

2013 ◽  
Vol 1505 ◽  
Author(s):  
Krzysztof Fic ◽  
Mikolaj Meller ◽  
Grzegorz Lota ◽  
Elzbieta Frackowiak
Keyword(s):  
Activated Carbon ◽  
Redox Reactions ◽  
Electrode Materials ◽  
Activated Carbons ◽  
Hydroxyl Group ◽  
Carbon Surface ◽  
Carbon Electrodes ◽  
Main Subject ◽  
Solution Ph ◽  
Reversible Redox

ABSTRACTThe main subject of this paper is to examine and to evaluate the capacitive behaviour of activated carbon electrodes electrochemically decorated by quinone-type functional groups. For this purpose, different electrolytes, i.e. hydroquinone, catechol and resorcinol at the concentration of 0.38 mol L-1, dissolved in 1 mol L-1 H2SO4, 1 mol L-1 Li2SO4 and 6 mol L-1 KOH were used. These electrolytes could generate electroactive groups (able to undergo reversible redox reactions) on the surface of electrode material. Apart from typical adsorption of the mentioned dihydroxybenzenes, so called grafting could occur and might cause generation of quinone|hydroquinone functionals on carbon surface. As an effect of functional reversible redox reaction, additional capacitance value, called pseudocapacitance, could be achieved. Hence, besides typical charge originating from charging/discharging of the electrical double layer on the electrode/electrolyte interface, additional capacitance comes also from faradaic reactions. Activated carbons are the most promising electrode materials for this purpose; apart from great physicochemical properties, they are characterized by well-developed specific surface area over 2000 m2 g-1 which results in high capacitance values.In the manuscript the influence of the hydroxyl group location as well as electrolyte solution pH on the electrochemical performance of the electrode is discussed.

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