Search results for "supporting"

Metal‐Free Electrochemical Synthesis of Sulfonamides Directly from (Hetero)arenes, SO2, and Amines

2021

Abstract Sulfonamides are among the most important chemical motifs in pharmaceuticals and agrochemicals. However, there is no methodology to directly introduce the sulfonamide group to a non‐prefunctionalized aromatic compound. Herein, we present the first dehydrogenative electrochemical sulfonamide synthesis protocol by exploiting the inherent reactivity of (hetero)arenes in a highly convergent reaction with SO2 and amines via amidosulfinate intermediate. The amidosulfinate serves a dual role as reactant and supporting electrolyte. Direct anodic oxidation of the aromatic compound triggers the reaction, followed by nucleophilic attack of the amidosulfinate. Boron‐doped diamond (BDD) electro…

The correlation between electrochemical impedance spectra and voltammograms of PB films in aqueous NH4Cl and CsCl

1998

Abstract Voltammetric curves of reduction of Prussian Blue Films to the Everitt’s Salt form and oxidation to the Prussian Yellow form show important differences depending on the supporting electrolyte countercation. The rate of the overall electron-hopping depends on the countercation. Apparent diffusion coefficients are evaluated from impedance spectra at different stabilization potentials. The dependence of the apparent diffusion coefficients on the stabilization potential can help understand the dependence of the voltammograms shape on the countercation nature.

Electrochemical Oxidation of Carboxylic Acids in Water at Boron-Doped Diamond (BDD) Anodes in the Range of Potential of Oxygen Evolution: Detection M…

2013

The electrochemical oxidation in water solutions of selected carboxylic acids (namely oxalic, formic, acetic, maleic, and succinic) at boron-doped diamond (BDD) anodes was investigated by polarization and chronoamperometric measurements. In the presence of low concentrations of carboxylic acids, current densities changed approximately linearly with the acid concentrations. Furthermore, when the current densities were plotted as a function of the chemical oxygen demand, a similar response was observed for all the investigated acids with the exception of oxalic acid. For high carboxylic acid concentrations, the linear variation is often loosen and different behaviors are observed depending on…

Electrochemical behaviour of inorganic redox substances dispersed into Nafion® films

1999

Abstract The voltammetric response of a Nafion ® film deposited on an indium tin oxide (ITO) electrode was studied. It was observed that the response is affected by the thickness of the Nafion ® layer. Also, the voltammograms show differences depending on the concentration and composition of the supporting electrolyte solution. The ITO–Nafion ® system can be stabilised by repetitive cyclic voltammetry, and then the inner hydrogen reduction is not detected by electrochemical impedance spectroscopy. Different substances were dispersed into the Nafion ® matrix in order to study their electrochemical response.

Studien zum Vorgang der Wasserstoffübertragung, 41. Elektroreduktion von Acetophenon unter Mitwirkung optisch aktiver Leitsalze

1977

Die Anderung des Carbinol/Pinakol-Verhaltnisses2) (C/P) und der optischen Induktion bei der Elektroreduktion von Acetophenon mit (1 R, 2S)-N-(3-Cyanpropyl)-N-methylephedriniumbromid (1) und (1 R, 2 S)-N,N-Dimethylephedriniumbromid (2) als Leitsalze wird untersucht in Abhangigkeit: a) vom Potential (Tabelle 1), b) von der Stromdichte (Tabelle 2), c) von Pulsbedingungen (Tabelle 3), d) vom pH (Tabelle 4), e) von der Anwesenheit anderer Kationen (Tabelle 5), f) vom Losungsmittel (Tabelle 6), g) von der Temperatur (Tabelle 7) und h) von der Art des Elektrodenmaterials (Tabelle 8). — Es werden tensammetrische und cyclovoltammetrische Messungen durchgefuhrt. Die in trockenem Dimethylformamid erha…

The electrochemistry of carbon monoxide reductive cyclotetramerization to squarate anion

1978

Abstract The electrochemical reduction, of carbon monoxide to C4O2−4 squarate anion is investigated. Particular attention is devoted to the influence that solvents, electrolytes, electrodes and carbon monoxide pressure have on the yields. The main feature appears to be that strictly controlled conditions are not necessary for cyclotetramerization. In dmf — Bu4NBr the following yields vs reacted CO and circulated charge were obtained with different cathodes: Pt(49%, 34%); Au(48%, 29%); Al(47%, 38%); stainless steel (36%, 33%); graphite (39%, 31%). A distinct influence of the supporting electrolyte (inorganic and tetraalkylammonium halides) was however observed.

Podpora zručnosti triedit' u deti predškolského veku

2014

DOCTORAL: THE FREE APP FOR TUTORING IN SUPPORTIVE ORAL CARE

2018

To introduce the version 2.0 of DoctOral free app, created for tutoring medical/dental professionals (and students) in the clinical recognition of oral lesions and dental treatment planning in patients at risk of ONJ drug- related.

Kształtowanie intuicji matematycznych w trakcie pozaszkolnej aktywności dziecka

2016

Rodzice jako partnerzy procesu rozbudzania dziecięcej aktywności matematycznej

2017

Children learn in a spontaneous and continuous way: when they look at an object, paying more attention to it, or when they notice something accidentally, when they perform simple actions of daily routine, or even when they turn to a grown-up with a question. Therefore, forming proper mathematical intuition should not be limited merely to activities at school, but should proceed natural, also during everyday activities, while playing games or talking to other children or the parents. The individual’s own activity plays a particular role in the development of mathematical skills in children. And it is parents who have the greatest say as regards the lines along which the child’s activity is d…