Click Chemistry and Nitrogen-Containing Heterocycles Formed in Surface Functionalization Reactions

Abstract The stepwise functionalization of surfaces with molecules or biomolecules is of increasing interest in the fields of electronics, sensing, catalysis, solar energy, and medicine. The bound molecules lend new properties and reactivity to surfaces of metals, carbon‐based materials, nanostructured metal oxides, and quantum dots. Click chemistry is, to date, the most successful and versatile method to immobilize molecules onto surfaces in a stepwise fashion. The click reactions require mild conditions, are highly (bio‐)orthogonal, regio‐ and stereo‐specific, use reagents that are compatible with many surfaces, do not produce by‐products that require separation procedures, and are concentration independent. Recent variations of click chemistry allow photopatterning with excellent control of the surface chemistry. This chapter examines the properties and scope of click reactions that lead to the formation of nitrogen‐containing heterocycles during the surface functionalization step. The focus is on nanostructured surfaces that were very difficult to functionalize prior to the development of click chemistry. The chapter ends with an outlook on areas that are still relatively underdeveloped: stronger contribution of theory for click at interfaces is needed, there are very few examples of reversible click methods, and the electronic properties of the nitrogen heterocycles that are formed during the click remain little explored.