Out of equilibrium operation of chemical reaction networks (CRNs) enables artificial materials to autonomously respond to their environment by activation and deactivation of intermolecular interactions. Generally, their activation can be driven by various chemical conversions, yet their deactivation to non-interacting building blocks remains largely limited to hydrolysis and internal pH change. To achieve control over deactivation, we present a new, modular CRN that enables reversible formation of positive charges on a tertiary amine substrate, which are removed using nucleophilic signals that control the deactivation kinetics. The modular nature of the CRN enables incorporation in diverse polymer materials, leading to a temporally programmed transition from collapsed and hydrophobic to solvated, hydrophilic polymer chains by controlling polymer-solvent interactions. Depending on the layout of the CRN, we can create stimuli-responsive or autonomously responding materials. This concept will not only offer new opportunities in molecular cargo delivery but also pave the way for next-generation interactive materials.

Acylhydrazones formation has been widely applied in materials science and biolabeling. However, their sluggish condensation rate under neutral conditions limits its application. Herein, indolines with electron-donating groups are reported as a new catalyst scaffold, which can catalyze acylhydrazone, hydrazone, and oxime formation via an iminium ion intermediate. This new type of catalyst showed up to 15-fold rate enhancement over the traditional anilinecatalyzed reaction at neutral conditions. The identified indoline catalyst was successfully applied in hydrogel formation.Letter pubs.acs.org/OrgLett

In certain tumor and diseased tissues, reactive oxygen species (ROS), such as H2O2, are produced in higher concentrations than in healthy cells. Drug delivery and release systems that respond selectively...

Chemical reaction networks (CRNs) that operate under constant influx of energy enable artificial materials to autonomously respond to their environment by activation and deactivation of intermolecular interactions. Generally, their activation can be driven by various energy sources, yet their deactivation to non-interacting building blocks remains largely limited to hydrolysis and internal pH change. To achieve control over deactivation, we developed a new CRN that enables reversible formation of positive charges on a tertiary amine substrate, which are removed using nucleophilic signals that control the deactivation kinetics. Incorporation of the CRN in a polymer material leads to a temporally programmed transition from collapsed and hydrophobic to solvated, hydrophilic polymer chains by controlling polymer-solvent interactions. Depending on the layout of the CRN, we can create stimuli-responsive or autonomously responding materials. This concept will not only offer new opportunities in molecular cargo delivery but also pave the way for next-generation interactive materials.

Chemical reaction networks (CRNs) that operate under constant influx of energy enable artificial materials to autonomously respond to their environment by activation and deactivation of intermolecular interactions. Generally, their activation can be driven by various energy sources, yet their deactivation to non-interacting building blocks remains largely limited to hydrolysis and internal pH change. To achieve control over deactivation, we developed a new CRN that enables reversible formation of positive charges on a tertiary amine substrate, which are removed using nucleophilic signals that control the deactivation kinetics. Incorporation of the CRN in a polymer material leads to a temporally programmed transition from collapsed and hydrophobic to solvated, hydrophilic polymer chains by controlling polymer-solvent interactions. Depending on the layout of the CRN, we can create stimuli-responsive or autonomously responding materials. This concept will not only offer new opportunities in molecular cargo delivery but also pave the way for next-generation interactive materials.