Isomer effects in the extraction of metal ions from acidic nitrate media by dicyclohexano-18-crown-6

The extraction of strontium and potassium from nitric acid by the cis-syn-c is and cis-anti-cis isomers of dicyclohexano-18-crown-6 (DCH18C6) in l-octa nol is examined. Both isomers are shown to extract significant amounts of u ndissociated nitric acid. This extraction, along with the formation of meta l-nitrate and metal-crown ether complexes in the aqueous phase, is shown to be important in determining the efficiency of metal ion extraction by the two isomers. The DCH18C6 isomer yielding the more efficient extraction of p otassium or strontium is shown to depend upon the crown ether concentration and the aqueous nitric acid concentration.