Design and synthesis of a new class of nonmacrocyclic alkali metal host compounds

[GRAPHICS] A new class of nonmacrocyclic metal ion hosts has been examined that featur es a polyspirocyclic framework that offers a 1,3,5-triaxial presentation of ligating centers. These compounds are easily synthesized and exploit stere oelectronic influences to preorganize the metal ion binding site. While com pounds bearing oxygen substituents (X = OH, OMe) failed to show appreciable binding of alkali metals, the aminated host (X = NHBn) exhibitied strong b inding with association constants (K-a) greater than 10(7)-10(8) as measure d by picrate extraction analysis.