Metal salt extraction

Chun, S., Dzyuba, S. V., Bartsch, R. A., Influence of structural variation in room-temperature ionic liquids on the selectivity and efficiency of competitive alkali metal salt extraction by a crown ether. Anal. Chem., 73,3737-3741,2001. 

The bifunctional extractant octyl(phenyl)-V,V -diisobutylcarbamoylmethylphos-phine oxide and related compounds (16,17) were also studied by SANS to elucidate the size and shape of the macromolecular aggregates formed during metal salt extraction. 

Galbraith, S. G., Plieger, P. G., and Tasker, P. A. (2002) Cooperative sulfate binding by metal salt extractants containing 3-dialkylaminomethylsalicylaldimine units, Chem. Commun. (22), 2662-2663. 

Thus the assembly is pre-organized for metal ion uptake and no counter-anion transport into the organic phase is necessary. In other studies, it has also been demonstrated that another self-organization process involving azacrown compounds has allowed metal salt extraction against that counters the Hofmeister series for the anions involved [50]. 

Metal salt extraction at a fixed reactant concentration (0.5 M) will cause a similar proton shift to a higher field from acid to base, as illustrated in Fig. 11 for the extraction of ZnCb from an aqueous solution. 

The efficiency and selectivity of metal salt extraction by ABC extractants and their dependence on extractant composition, aqueous phase composition, pH, and temperature have been reviewed and analyzed [30,31]. 

On metal salt extraction by ABC extractants the anion A of the water-immiscible acid present in the extractant (HA) binds cationic species, as in the case of liquid cation exchangers, but without releasing a proton to the aqueous solution. The amine cation B" or BH binds the anion of the salt as well as anionic complexes, if formed between the cation and the various anions (including those of the water-immiscible acid). On acid extraction, protons come instead of the metal salt cations. The mechanisms might be quite similar to that of extracting salts of cations not capable of forming... 

Chxm, S. Dzyuba, S.V. Bartsch R.A. (2001) Influence of Structural Variation in Room-Temperature Ionic Liquids on the Selectivity and Efficiency of Competitive Alkali Metal Salt Extraction by a Crown Ether, Anal. Chem., 73 3737-3741. 

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