III reduction

A simple application of the reaction may bo mentioned. Refluxing of (I) with 48 per cent, hydrobromic aeid and glacial acetic acid leads to hydrolysis and decarboxylation and the production of a mixture of the yl tctone yr-di-phonylbutyrolaotone (II) and the isomeric unsaturated acid yY-dlphenyl-vinylacotic acid (III) reduction by the Clemmonsen method or catalytically... 

The sorption evaluation of Pd(II) micro-amounts by active coals, ACs, from solutions with 50-500-fold excess of accompanying metals compounds was shown [1]. From the other hand catalytic action of Pd(II) in reaction of Mn(III) reduction by Ck is used for Pd(II) micro-amounts determination by catalytic method [2]. The co-operation of soi ption and catalytic detenuination of Pd(II) in one process was investigated. 

It was found that sorbed palladium might catalyse reaction of Mn(III) reduction by Cf not only after it s removing from coal, but AC with palladium, Pd/AC, has also his own catalytic effect. On the base of dependence between characteristics of AC, chemical state of palladium on AC surface and catalytic action of Pd/AC in indicator reaction it might establish, that catalytic action concerns only to non-reduced or partly reduced palladium ions connected with chloride ions on coal surface. The presence or absence of catalytic action of Pd/AC in above-mentioned reaction may be proposed for determination of chemical state of palladium on AC surface. Catalytic effect was also used for palladium micro-amounts determination by soi ption-catalytic method. 

When a solution of chromic and sulfuric acids in water is added at 0-20° to an alcohol or formate dissolved in acetone, a rapid oxidation takes place with the separation of the green chromium III reduction product as a separate layer. This system is commonly known as Jones reagent. The rate of oxidation is so fast that it is often possible to run the reaction as a titration to an... 

Reductant equivalent weights of, 847 Reduction 409 by chromium(II) salts, 409 by hydrogen sulphide, 416 by Jones reductor (zinc amalgam), 410 by liquid amalgams, 412 by silver reductor, 414 by sulphurous acid, 416 by tin(II) chloride, 415 by titanium(II[), 410 by vanadium(II), 410 see also Iron(III), reduction of Reduction potentials 66 Reference electrodes potentials, (T) 554 Relative atomic masses (T) 819 Relative error 134 mean deviation, 134... 

Xenon trioxide is reduced in aqueous solution, in a thermal reaction by Pu(III) and photochemically by Np(V). The stoichiometry of the Pu(III) reduction is... 

The As(III) reduction is also catalysed by Fe(III) with radical-chain kinetics . ... 

Childers SE and DR Lovley (2001) Differences in Fe(III) reduction in the hyperthermophilic archaeon, Pyrob-aculum islandicum, versus mesophilic Fe(III)-reducing bacteria. FEMS Microbiol Lett 195 253-258. 

He Q, RA Sanford (2003) Characterization of Fe(III) reduction by chlororespiring Anaeromyxobacter dehalogenans. Appl Environ Microbiol 69 2712-2718. 

Saffarini DA, SL Blumerman, KJ Mansoorabadi (2002) Role of menaquinones in Fe(III) reduction by membrane fractions of Shewanella putrefaciens. J Bacteriol 184 846-848. 

Using electrons for the electrolytic reduction of metal salts, Reetz and coworkers have introduced a further variation to the tetraalkylammoniumhalide-stabilization mode [192-198]. The overall electrochemical process can be divided into the following steps (i) oxidative dissolution of the sacrificial Metbuik anode, (ii) migration of Met ions to the cathode, (iii) reductive formation of... 

Aerobic respiration Denitrification Mn(IV) reduction Fe(III) reduction Sulfate reduction Methane fermentation Nitrogen fixation... 

It has been reported that the sonochemical reduction of Au(III) reduction in an aqueous solution is strongly affected by the types and concentration of organic additives. Nagata et al. reported that organic additives with an appropriate hydro-phobic property enhance the rate of Au(III) reduction. For example, alcohols, ketones, surfactants and water-soluble polymers act as accelerators for the reduction of Au(III) under ultrasonic irradiation [24]. Grieser and coworkers [25] also reported the effects of alcohol additives on the reduction of Au(III). They suggested that the rate of the sonochemical reduction of Au(III) is related to the Gibbs surface excess concentration of the alcohol additives. 

Figure 5.7 shows the effects of the distance from the oscillator to the bottom of the reaction vessel on the rate of Au(III) reduction, where the distance is changed from 3.5 to 4.5 mm [29]. It is clear that the rates of reduction are affected by the position of the reaction vessel. The rate of reduction became the maximum at a distance of ca. 3.8 mm. This was almost the same as the half-wavelength of the ultrasound (3.71 mm) used in this study. It is suggested that ultrasound is effectively transmitted into the reaction vessel at 3.8 mm distance. It should be noted that the position of the reaction vessel sensitively affects the efficiency of the sonochemical reduction. 

Fig. 5.7 Rate of Au(III) reduction as a function of the distance between the reaction vessel and the oscillater. Conditions 1 mM Au(III),...

Fig. 5.10 Relation between the rate of Au(III) reduction and the average size of the formed gold particles. Each error bar corresponds to the standard deviation of the size of the gold particles. Closed circles correspond to the dependence of the ultrasound intensities, in which the rate of reduction increases with increasing the intensity. Conditions 200 kHz.

The rate of Au(III) reduction is also affected by ultrasound frequency as seen in Fig. 5.8. From TEM analyses, the size of the formed Au nanoparticles was found to be affected by ultrasound frequency. Figure 5.11 shows the relationship between the average size of the formed Au nanoparticles and the rate of Au(III) reduction. It is found that, even in the case of different frequency, the rate of Au(III) reduction affects the size of the formed Au nanoparticles. Based on the obtained results, the nucleation process is important in determining the size of Au particles, because the nucleation process should be closely related to the rate of reduction [29, 33],... 

Okitsu K, Yue A, Tanabe S, Matsumoto H, Yobiko Y, Yoo Y (2002) Sonolytic control of rate of gold(III) reduction and size of formed gold nanoparticles relation between reduction rates and sizes of formed nanoparticles. Bull Chem Soc Jpn 75 2289-2296... 

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