Complexation-driven assembly of imine-linked helical receptors showing adaptive folding and temperature-dependent guest selection

The development of synthetic receptors capable of selectively binding guests with diverse structures and multiple functional groups poses a significant challenge. Here, we present the efficient assembly of foldamer-based receptors for monosaccharides, utilising the principles of complexation-induced equilibrium shifting and adaptive folding. Diimine 4 can be quantitatively assembled from smaller components when d -galactose is added as a guest among monosaccharides we examined. During this assembly, dual complexation-induced equilibrium shifts toward both the formation of diimine 4 and the conversion of d -galactose into α- d -galactofuranose are observed. Diimine 6 is quantitatively assembled in the presence of two different guests, methyl β- d -glucopyranoside and methyl β- d -galactopyranoside, resulting in the formation of two dimeric complexes: ( 6 - MP ) 2 ⊃(methyl β- d -glucopyranoside) 2 and ( 6 - MM ) 2 ⊃(methyl β- d -galactopyranoside∙2H 2 O) 2 , respectively. These two complexes exhibit distinct folding structures with domain-swapping cavities depending on the bound guest and temperature. Interestingly, ( 6 - MM ) 2 ⊃(methyl β- d -galactopyranoside∙2H 2 O) 2 is exclusively formed at lower temperatures, while ( 6 - MP ) 2 ⊃(methyl β- d -glucopyranoside) 2 is only formed at higher temperatures.