Lithium Ion-Selective Binding Properties of a Conformationally Constrained Tris(spirotetrahydrofuran) Secured to an Inositol Orthoformate Platform

[structure: see text] The C3V-symmetric triaxially locked trispirotetrahydrofuran 2 binds Li+ ions strongly and Na+ ions much less effectively. The observed discrimination factor is attributed to greater structural preorganiztion and lower solvation prior to selective complexation, and particularly to the formation of a 2:1 sandwich complex involving lithium. 13C NMR studies have defined a reluctance to form a 1:1 species when excess Li+ is present.