444 research outputs found
Multi-vanadium substituted polyoxometalates as efficient electrocatalysts for the oxidation of l-cysteine at low potential on glassy carbon electrodes
The electrochemical behaviours of the sandwich-type complex
[As2W18(VO)3O66]11- were studied in a pH 7 medium and compared with those of
the three following Dawson-type vanadium-substituted complexes: [P2V2W16O62]8-
(P2V2W16), [P2MoV2W15O62]8- (P2MoV2W15) and [P2V3W15O62]9- (P2V3W15).
Electrochemistry shows that the sandwich-type POM contains 2 VIV centers and
one VV center and must be formulated As2V2IVVW18, in agreement with titration,
elemental analysis and magnetic measurements on this element.. All the POMs of
this work proved efficient for the oxidation of L-cysteine. Comparison of the
present results with those of mono-Vanadium substituted POMs indicates that
accumulation of vanadium atoms in the POM framework is beneficial in the
electrocatalytic process. In addition, the present work highlights the
important influence of the POM structure in the electrocatalytic oxidation of
L-cysteine. The remarkable outcome of this work is that the potential for the
oxidation of L-cysteine in the presence of the selected POMs has been
substantially driven in the negative direction compared to the case of glassy
carbon alone, a feature which is associated with faster kinetics. The stability
of the systems must also be pointed out
Evidence for a p dimer in the electrochemical reduction of 1,3,5-trinitrobenzene : a reversible N2-fixation system
Premi a l'excel·lĂšncia investigadora. Ămbit de les CiĂšncies Experimentals. 200
Redox Behavior of Anticancer Chalcone on a Glassy Carbon Electrode and Evaluation of its Interaction Parameters with DNA
The interaction of anticancer chalcone [AMC, 1-(4âČ-aminophenyl)-3-(4-N,N-dimethylphenyl)-2-propen-1-one] with DNA has been explored using electrochemical, spectroscopic and viscometric techniques. A shift in peak potential and decrease in peak current were observed in cyclic voltammetry and hypochromism accompanied with bathochromic shift were noticed in UV-Vis absorption spectroscopy. These findings were taken as evidence for AMC âDNA intercalation. A binding constant (K) with a value of 6.15 Ă 105 Mâ1 was obtained from CV data, which was also confirmed by UV-Vis absorption titration. Moreover, the diffusion coefficient of the drug with and without DNA (Db and Du), heterogeneous electron transfer rate constant (ko) and electron affinity (A) were also calculated from electrochemical data
Linear sweep voltammetry: kinetic control by charge transfer and/or secondary chemical reactions
Sur deux composés nominaux plautiniens : multibibus et merobibus
Nadjo Léon. Sur deux composés nominaux plautiniens : multibibus et merobibus. In: L'Information Grammaticale, N. 42, 1989. pp. 9-11
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