Green reductant

Prevot reported on Janus green reduction methods with a number of different organisms 3 32. 

FIGURE 12.23. Traditional and green reductions of a nitro compound. (Source Tsukinoki and Hirohisa, 2001). 

Reduction of vitamin BJ2 with zinc in ammonium chloride solution or with aqueous solutions containing borohydride affords a gray-green reduction product called vitamin B12s (224). It has been suggested that the reduced product is a hydride (66, 176, 184, 219), since it has some reactions that are analogous to those of metal-hydrogen complexes (26) (see Fig. 10) and the method of preparation is similar to that for... 

The catalytic action of is nearly specific only molybdenum reacts analogously, but the effect is less pronounced. Other metal ions that can be reduced by Ti have no such effect on the malachite green reduction. Despite the specific catalytic action, consideration must be given to the... 

This approach basically consists of an electrolytic reduction of copper salts, carried out in a nonconventional IL solvent. The technique exploits electrons as the green reductant and the IL as the green solvent. In contrast to the relatively narrow potential window of water or other solvents, ILs offer wider electrochemical windows, combined with a stabilizing effect capable of preventing the aggregation of kinetically unstable nanoparticles [334]. Wang and coworkers [335] have recently used this technique for the conversion of CuCl into copper nanoparticles. 

After 60-min photoirradiation, FA was almost completely converted to CO2 and /m-ABS was obtained with >99 % yield. Therefore, only m-ABS was present in the aqueous phase after 60 min. Since it is not necessary to remove the hole scavenger (FA), carbmiate ion generated by oxidation of FA, unreacted substrate (w-NBS), intermediates (/m-NSBS and /n-PHAS), and by-product(s), it can be concluded that this photoreaction system is a green reduction process. 

Vanadium II) forms green V2(S04)3 (electrolytic or Mg reduction of V2O5 in H2SO4). Alums and other double salts are formed. 

The + 2 oxidation state is achieved by more drastic reduction (zinc and acid) of the -1-5. -I- 4 or -t- 3 states thus addition of zinc and acid to a solution of a yellow vanadate(V) gives, successively, blue [VOfH O) ]", green [VCl2(H20)4] and violet [VfH O)... 

The reduction of catalysts warranted the additional stir time. 96 hours maybe excessive, I believe they were hoping it would turn green and the longerthey waited the more they thought it was a lost cause. Fortunately it worked out on the +++ side )"... 

Nitrates. Iron(II) nitrate hexahydrate [14013-86-6], Fe(N03)2 6H20, is a green crystalline material prepared by dissolving iron in cold nitric acid that has a specific gravity of less than 1.034 g/cm. Use of denser, more concentrated acid leads to oxidation to iron(III). An alternative method of preparation is the reaction of iron(II) sulfate and barium or lead nitrate. The compound is very soluble in water. Crystallisation at temperatures below — 12°C affords an nonahydrate. Iron(II) nitrate is a useful reagent for the synthesis of other iron-containing compounds and is used as a catalyst for reduction reactions. 

The unstable pale blue-green bis(2,276, 2 -terpyridine)iron(3+) ion [47779-99-7], [Fe(terpy)2], has been obtained by oxidation of [Fe(terpy)2]. It is very unstable with respect to reduction by solvent and ligand dissociation. The perchlorate salt [2153642-5] has been reported. 

Plutonium(III) in aqueous solution, Pu " ( 4)> is pale blue. Aqueous plutonium(IV) is tan or brown the nitrate complex is green. Pu(V) is pale red-violet or pink in aqueous solution and is beUeved to be the ion PuO Pu(VI) is tan or orange in acid solution, and exists as the ion PuO. In neutral or basic solution Pu(VI) is yellow cationic and anionic hydrolysis complexes form. Pu(VII) has been described as blue-black. Its stmcture is unknown but may be the same as the six-coordinate NpO (OH) (91). Aqueous solutions of each oxidation state can be prepared by chemical oxidants or reductants... 

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