Impact of NDI‐Core Substitution on the pH‐Responsive Nature of Peptide‐Tethered Luminescent Supramolecular Polymers

The pH‐responsive nature of two self‐assembled NDI‐peptide amphiphile conjugates is reported. The diethoxy substituted NDI showed a pH‐dependent assembly behaviour, as expected. In contrast, the isopropylamino‐ and ethoxy‐substituted NDI based supramolecular polymer was stable at acidic and basic aqueous conditions. This finding highlights how subtle changes in the molecular design of π‐stacked chromophore‐peptide conjugates have a drastic impact on their equilibrium structure and ultimately functional properties. Small changes ‐ big impact! Peptide tethered π‐conjugate chromophores combine the stimuli‐responsive nature of self‐assembled oligopeptide designs with the tunable optical properties of organic semiconductors. In this contribution, we discuss how subtle changes in the molecular design of core substituted naphthalene diimide‐peptide conjugates have a drastic impact on the pH‐responsive nature of the supramolecular polymerization process in water.