Effective Coordination of Electron-Donating Sidearms of Double-Armed 15-Crown-5 Ethers toward Alkali Metal Cations.

Two kinds of positional isomers of double-armed crown ethers containing quinoline moieties in the sidearms were prepared and the participation of their sidearms in the complexation with alkali metal cations was examined. The difference in the position of the two sidearms on the crown ring was found to remarkably affect the complexadon properties toward alkali metal cations when both sidearms are cis configuration to the crown ring.