Extraction of aurocyanide ion-pairs by poly(oxyethylene) extractants.
Aurocyanide ion-pairs with alkali-metal ions are extracted efficiently into organic phases with the aid of long-chain polyethers. The results of distribution experiments can be rationalized by molecular mechanics calculations. The polyether is shown to co-ordinate to the alkali-metal cation through the ether oxygen atoms, wrapping around the cation in a helical configuration. High extraction efficiencies are obtained with high dielectric-constant solvents, which tend to stabilize the helical polyether-cation complex. The preferential secondary solvation of the aurocyanide anion by the chosen solvents also has an important influence on the extraction efficiency.
Adams
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Mintek, Private Bag X3015, Randburg 2125, South Africa.
Wade
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Hancock
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