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

Abstract

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.