MULTI-LOOP CROWN ETHERS WITH MULTIPLE SELECTIVITY

In the crown ether combinations of types 1 and 2, several rings having variable cavity sizes (and soner complements) are linked via spiro‐C atoms. These novel complexing agents should be valuable not only for the analysis of mixture of salts but also for enyme‐analogous fixation of polyfunctional organic compounds. They might also be of use for simultaneous, and hence profitable, recovery of several precious metals from seawater. (Figure Presented.) Copyright © 1979 by Verlag Chemie, GmbH, Germany