scholarly journals Electrochemical Studies of Chlorine Containing Silanes

2021 ◽  
Author(s):  
Mark Hoddenbagh ◽  
Daniel Foucher ◽  
Dennis Worsfold
Keyword(s):  
Cyclic Voltammetry ◽  
Reduction Potential ◽  
Electrolyte Concentration ◽  
Electrochemical Studies ◽  
Reduction Potentials ◽  
Solvent Type

The reduction potentials of a series of mono-, di- and trichloro alkyl and aryl substituted silanes was investigated by cyclic voltammetry. It was shown that chlorosilanes can be reduced in two one electron steps at potentials more positive than -1V vs SCE. The solvent type (THF, MeCN), silane type and polymerization and electrolyte concentration were varied and found to greatly impact the reduction potential.

scholarly journals One-Electron Reduction Potentials: Calibration of Theoretical Protocols for Morita–Baylis–Hillman Nitroaromatic Compounds in Aprotic Media

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2129 ◽  
Author(s):  
Amauri Francisco da Silva ◽  
Antonio João da Silva Filho ◽  
Mário Vasconcellos ◽  
Otávio Luís de Santana
Keyword(s):  
Cyclic Voltammetry ◽  
Biological Activity ◽  
Chemical Structure ◽  
Reduction Potential ◽  
Chemical Reactivity ◽  
Nitroaromatic Compounds ◽  
Reduction Potentials ◽  
Electron Reduction ◽  
The One ◽  
Antileishmanial Activities

Nitroaromatic compounds—adducts of Morita–Baylis–Hillman (MBHA) reaction—have been applied in the treatment of malaria, leishmaniasis, and Chagas disease. The biological activity of these compounds is directly related to chemical reactivity in the environment, chemical structure of the compound, and reduction of the nitro group. Because of the last aspect, electrochemical methods are used to simulate the pharmacological activity of nitroaromatic compounds. In particular, previous studies have shown a correlation between the one-electron reduction potentials in aprotic medium (estimated by cyclic voltammetry) and antileishmanial activities (measured by the IC50) for a series of twelve MBHA. In the present work, two different computational protocols were calibrated to simulate the reduction potentials for this series of molecules with the aim of supporting the molecular modeling of new pharmacological compounds from the prediction of their reduction potentials. The results showed that it was possible to predict the experimental reduction potential for the calibration set with mean absolute errors of less than 25 mV (about 0.6 kcal·mol−1).

scholarly journals Mutually Isomeric 2- and 4-(3-Nitro-1,2,4-triazol-1-yl)pyrimidines Inspired by an Antimycobacterial Screening Hit: Synthesis and Biological Activity against the ESKAPE Panel of Pathogens

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 666
Author(s):  
Sergey Chuprun ◽  
Dmitry Dar’in ◽  
Elizaveta Rogacheva ◽  
Liudmila Kraeva ◽  
Oleg Levin ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Antibacterial Activity ◽  
Reduction Potential ◽  
Gram Negative ◽  
Reduction Potentials ◽  
Apparent Correlation ◽  
Electron Reduction ◽  
Activity Loss ◽  
Eskape Pathogens ◽  
Bioactivity Profile

Starting from the structure of antimycobacterial screening hit OTB-021 which was devoid of activity against ESKAPE pathogens, we designed, synthesized and tested two mutually isomeric series of novel simplified analogs, 2- and 4-(3-nitro-1,2,4-triazol-1-yl)pyrimidines, bearing various amino side chains. These compounds demonstrated a reverse bioactivity profile being inactive against M. tuberculosis while inhibiting the growth of all ESKAPE pathogens (with variable potency patterns) except for Gram-negative P. aeruginosa. Reduction potentials (E1/2, V) measured for selected compounds by cyclic voltammetry were tightly grouped in the −1.3–−1.1 V range for a reversible single-electron reduction. No apparent correlation between the E1/2 values and the ESKAPE minimum inhibitory concentrations was established, suggesting possible significance of other factors, besides the compounds’ reduction potential, which determine the observed antibacterial activity. Generally, more negative E1/2 values were displayed by 2-(3-nitro-1,2,4-triazol-1-yl)pyrimidines, which is in line with the frequently observed activity loss on moving the 3-nitro-1,2,4-triazol-1-yl moiety from position 4 to position 2 of the pyrimidine nucleus.

Octafluoro[2.2]paracyclophane (AF4) Quinone

2008 ◽  
Vol 73 (12) ◽  
pp. 1764-1776
Author(s):  
Wei Xu ◽  
William R. Dolbier ◽  
Jian-Xin Duan ◽  
Yian Zhai ◽  
Katsu Ogawa ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Reduction Potential ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

Octafluoro[2.2]paracyclophane (AF4) has been oxidized by treatment with HIO3 in CF3CO2H to form the corresponding p-quinone along with a unique triketone. This quinone undergoes reduction to the respective hydroquinone as well as a Diels-Alder reaction with 1,3-cyclohexadiene. Its reduction potential was obtained by cyclic voltammetry and is discussed in the context of other quinones.

scholarly journals Spectral Probe for Electron Transfer and Addition Reactions of Azide Radicals with Substituted Quinoxalin-2-Ones in Aqueous Solutions

2021 ◽  
Vol 22 (2) ◽  
pp. 633
Author(s):  
Konrad Skotnicki ◽  
Slawomir Ostrowski ◽  
Jan Cz. Dobrowolski ◽  
Julio R. De la Fuente ◽  
Alvaro Cañete ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Density Functional ◽  
Reduction Potential ◽  
Biological Significance ◽  
Radical Cations ◽  
Basis Sets ◽  
Double Bonds ◽  
Reduction Potentials

The azide radical (N3●) is one of the most important one-electron oxidants used extensively in radiation chemistry studies involving molecules of biological significance. Generally, it was assumed that N3● reacts in aqueous solutions only by electron transfer. However, there were several reports indicating the possibility of N3● addition in aqueous solutions to organic compounds containing double bonds. The main purpose of this study was to find an experimental approach that allows a clear assignment of the nature of obtained products either to its one-electron oxidation or its addition products. Radiolysis of water provides a convenient source of one-electron oxidizing radicals characterized by a very broad range of reduction potentials. Two inorganic radicals (SO4●−, CO3●−) and Tl2+ ions with the reduction potentials higher, and one radical (SCN)2●− with the reduction potential slightly lower than the reduction potential of N3● were selected as dominant electron-acceptors. Transient absorption spectra formed in their reactions with a series of quinoxalin-2-one derivatives were confronted with absorption spectra formed from reactions of N3● with the same series of compounds. Cases, in which the absorption spectra formed in reactions involving N3● differ from the absorption spectra formed in the reactions involving other one-electron oxidants, strongly indicate that N3● is involved in the other reaction channel such as addition to double bonds. Moreover, it was shown that high-rate constants of reactions of N3● with quinoxalin-2-ones do not ultimately prove that they are electron transfer reactions. The optimized structures of the radical cations (7-R-3-MeQ)●+, radicals (7-R-3-MeQ)● and N3● adducts at the C2 carbon atom in pyrazine moiety and their absorption spectra are reasonably well reproduced by density functional theory quantum mechanics calculations employing the ωB97XD functional combined with the Dunning’s aug-cc-pVTZ correlation-consistent polarized basis sets augmented with diffuse functions.

RETRACTED: The Study of Composition and Morphology of Pd-Ag Alloy Powders by Electrodeposition

2017 ◽  
Vol 732 ◽  
pp. 81-85
Author(s):  
Chin Ming Chu ◽  
Shi Wen Yang ◽  
Shen Li Tsai ◽  
Wen Bing Yang
Keyword(s):  
Stainless Steel ◽  
Cyclic Voltammetry ◽  
Reduction Potential

Pd-Ag alloy powders were prepared on the stainless steel by DC electrodeposition. Cyclic voltammetry found the reduction potential of Pd, Ag and Pd-Ag. The composition and morphology of Pd-Ag were investigated by means of SEM, EDS.

scholarly journals Electrodeposition Behavior of Polycrystalline Ni–Mo–La Composite in Alkaline Solution

Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 299 ◽  
Author(s):  
Ning Li ◽  
Weizeng Chen ◽  
Lirong Lu ◽  
Chenghui Gao
Keyword(s):  
Cyclic Voltammetry ◽  
Alkaline Solution ◽  
Reduction Potential ◽  
Structural Phase ◽  
Reduction Process ◽  
Deposition Process ◽  
Nickel Ions ◽  
Ionic Activity ◽  
Lanthanum Ions ◽  
Metal Atoms

The polycrystalline Ni–Mo–La composite coating was obtained by electrodeposition through the addition of La3+ ions into Ni, Mo ions main salt weak alkaline solution. The obtained composite contain 0.92 at.% La. According to the law of ionic activity, the redox reaction of three kinds of metal atoms was studied by polarography and cyclic voltammetry. It was found that the addition of lanthanum ions changed the composite structural, phase, and element, and the OH− ions were deduced during the electrodeposition in alkaline solution. The introduction of lanthanum and molybdenum ions negatively shifted the reduction potential of nickel ions and broadened the peaks significantly in the deposition process, retarding the reduction and deposition rate of Ni ions, which was characterized by a multi-step reduction process of Mo and La metal atoms.

scholarly journals A Three-Step Approach to Estimation of Reduction Potentials of Natural Mixtures of Antioxidants Based on DPPH Test; Illustration for Catechins and Cocoa

Proceedings ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 4 ◽  
Author(s):  
Barbara Kusznierewicz ◽  
Monika Baranowska ◽  
Klaudia Suliborska ◽  
Wojciech Chrzanowski ◽  
Agnieszka Bartoszek
Keyword(s):  
Electrochemical Properties ◽  
Plant Extracts ◽  
Reduction Potential ◽  
Correlation Equation ◽  
Complex Mixtures ◽  
Test Results ◽  
Reduction Potentials ◽  
Dpph Test

The aim of this study is to propose a methodology to assess electrochemical properties of complex mixtures of antioxidants, such as plant extracts, based on the results of simple and popular DPPH test. The first, most difficult step, involves determinations of standard reduction potentials (E0) for the series of purified compounds (here catechins). The next step is the calculation of stoichiometric values (n10) based on the results of DPPH test for the same compounds. Finally, a correlation equation is formulated, which is then employed to estimate “cumulative reduction potential” (Ec) for the mixture of interest (here cocoa) using DPPH test results.

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