Intermolecular axial solvation of bound cations by sidearm donor groups inlariat ethers: formation of a supramolecular network

Previously studied disubstituted 4,13-diaza-18-crown-6 derivatives, R < N18 N > R, in which the substituents were cyanomethyl or propargyl did not show intramolecular, lariat-type cation solvation. The ring-bound cation in the propargyl derivative is solvated by the six macroring heteroatoms and apic ally by a bifurcated interaction of the type F . . .K+. . .F. In contrast, when the sidearm is cyanoethyl, an extended intermolecular network forms wh en the bound cation is either Na+ or K+. (C) 2001 Published by Elsevier Sci ence B.V.