Glucose binding drives reconfiguration of a dynamic library of urea-containing metal–organic assemblies

A bis-urea-functionalized ditopic subcomponent assembled with 2-formylpyridine and Fe^II, resulting in a dynamic library of metal–organic assemblies: an irregular Fe^II₄L₆ structure and three Fe^II₂L₃ stereoisomers: left- and right-handed helicates and a meso-structure. This library reconfigured in response to the addition of monosaccharide derivatives, which served as guests for specific library members, and the rate of saccharide mutarotation was also enhanced by the library. The (P) enantiomer of the Fe^II₂L₃ helical structure bound β-D-glucose selectively over α-D-glucose. As a consequence, the library collapsed into the (P)-Fe^II₂L₃ helicate following glucose addition. The α-D-glucose was likewise transformed into the β-D-anomer during equilibration and binding. Thus, β-D-glucose and (P)-3 amplified each other in the product mixture, as metal–organic and saccharide libraries geared together into a single equilibrating system.