15-Crown-5 and 18-crown-6 ethers bearing substituents on the ether ring have been studied as catalysts for the Finkelstein reaction and as agents for solubilization of alkali metal picratee in* heptane. All of these substituted crown ethers form stable complexes with Na+ and K+. These with highly lipophilic substituents are much more effective than the parent unsubstituted crown ethers as catalysts and as solubilizing agents. Both types of activity ...