“Silatranization”: Surface modification with silatrane coupling agents

Abstract

Silatranization, a specialized variant of silanization using silatrane compounds, is emerging as a powerful strategy to functionalize material surfaces. Compared to conventional silane coupling agents, silatranes exhibit remarkable hydrolytic stability and enhanced resistance to self-condensation, enabling controllable, water-independent formation of a polysiloxane self-assembled monolayer. This review critically examines the unique structure of silatranyl cages, emphasizing how the intramolecular N->Si bond and chelate effect modulate the silicon center's reactivity toward hydroxyl-decorated surfaces. The discussion encompasses a comprehensive comparison of silatranization and conventional silanization in the aspect of preparation of starting materials, deposition kinetics and morphology of resulting organic adlayer. Key reaction parameters – solvent choice, temperature, silatrane concentration and catalyst– are systematically evaluated to guide the design of efficient protocols. Strategies to remove triethanolamine byproduct are also outlined for achieving contaminant-free coatings. Additionally, analytical techniques (FT-IR, NMR, AFM, XPS) that allow to verify correct formation of a silatrane-derived self-assembled monolayer are presented. Finally, the review showcases wide-ranging applications underscoring how silatranes can provide durable, functional interfaces for metal oxides, glass and organic polymers. The insights collected here aim to accelerate future innovations in surface science and engineering through the robust and versatile approach of silatranization.