Linear‐to‐Turn Conformational Switching Induced by Deprotonation of Unsymmetrically Linked Phenolic Oligoamides

Proton-triggered conformational switching: Unsymmetrically linked phenolic oligoamides fold into a turn conformation from a linear conformation following the deprotonation of the phenol groups (see scheme). Deprotonation induces a rearrangement of the hydrogen-bonding mode within each unit from OH⋅⋅⋅OC (linear) to NH⋅⋅⋅O(oxyanion) such that all of the phenolate O− atoms are directed toward the inside of the turn.