FUNCTIONAL FOLDAMERS AS AMINE SENSORS AND CATION RECEPTORS

Abstract

This thesis describes the synthesis, structural properties and functions of two sets of hydrogen-bonded aromatic foldamers. The first set of foldamer molecules is derived from fluorescent oligophenol backbones and utilized to explore molecular recognition of amines. By engineering and optimizing oligophenol-based fluorescent backbones with built-in acid/base-sensitive conformational switches, we succeeded in uncovering an oligophenol hexamer that undergoes amine-induced conformational changes and fluorescence quenching to allow for patterned recognition of amines/ammonia. The second set of foldamer molecules is derived from monomeric methoxybenzene, fluorobenzne and pyridone motifs that are connected via amide bonds in different sequences and numbers to arrive at either circularly or helically folded hybrid structures. These hybrid foldamers contain interior cavities that are decorated by electron rich atoms and thus are able to bind metal ions. By adjusting the types and number of varying monomeric building blocks, these cation-binding cavities become tunable in terms of binding affinity and selectivity.