Donor–Acceptor Stenhouse Adducts for Stimuli-Responsive Self-Assembly of Gold Nanoparticles into Semiconducting Thin Films

Recent advancements in materials science and chemistry allowed the creation of intelligent, programmable materials. The stimuli-responsive substances are the most prominent candidates for developing sophisticated nanomachinery. Especially, photo- and thermoresponsive systems have gained much attention in recent years as elegant solutions for drug transportation, information storage, biomaterials, and material engineering. However, to this day, only a limited number of molecular domains display triggered and reversible self-organization at the water–oil interface. Among various substances functionalized with responsive moieties, the donor–acceptor Stenhouse adduct (DASA) stands out as an exciting but poorly explored tool in the toolbox of materials science. After being illuminated with a green light, the compound changes its coloration and polarity. This state can be reversed by increasing the temperature. The study presents the synthesis of gold nanoparticles (AuNPs) decorated with a DASA-containing ligand that can undergo on-demand, light-triggered, and thermoreversible self-organization at the water–oil interface. The layer of the nanoparticles locked at the interface can be successfully cross-linked, either by a dithiol molecule or via copper­(I)-catalyzed alkyne–azide cycloaddition (CuAAC). The latter option results in a composite with semiconducting properties. The research has the potential to impact the delivery systems for catalysis and the development of programmable materials with electroactive properties.