Abstract
Two series of benzocrown ether derivatives were prepared by treatment of 4'-chlorocarboxybenzocrown ethers (-15-crown-5 and -18-crown-6) with alkyl oligo (oxyethylene) ethers. Various aqueous solution properties, complexing stability constants with Na+ and K+, and the catalytic action on halogen-exchange reactions were examined for these compounds. The cloud point increased with increasing the number of oxyethylene units in the crown ring and/or in the side arm. Changes in the cloud points of the 18-crown series in the absence and presence of alkali metal chlorides suggest a good “host-guest” relationship between crown size and the kind of cation. Stability constants in methanol were not affected by introducing the side arm into benzocrowns, but the catalytic efficiencies of the two series of crowns increased with oxyethylene and alkyl chain length in the side arm.
