Ra. Sachleben et al., ION-PAIR EXTRACTION OF ALKALI-METAL NITRATE SALTS BY LIPOPHILIC, BENZO-SUBSTITUTED 24-CROWN-8 ETHERS, Separation science and technology, 32(1-4), 1997, pp. 275-284
The extraction of alkali metal nitrate salts by 24-crown-8 ethers bear
ing multiple benzo substituents has been surveyed in 1,2-dichloroethan
e diluent at 25 degrees C. The results reveal that the addition of ben
zo-substituents onto the 24-crown-8 increases both the extraction effi
ciency and the selectivity for the larger cations. Substitution of bra
nched alkyl groups onto the benzo rings of 24-crown-8 ethers has a rel
atively small influence on their extraction properties.