Metal phosphonates as supports for gold nanoparticles

The subject of this chapter was born from the blend of two different research areas: metal nanoparticles and solids with extended arrays. The confinement of a discrete number of metal atoms in the form of nanostructures paved the way to a new era for scientific research toward the development of innovative tools in several fields of application. The use of gold nanoparticles (AuNPs) in art dates back to ancient times, due to their ability to interact with visible light. Today, AuNPs and nanoclusters present opportunities for important applications in catalysis and biomedicine, among others. Due to their peculiar reactivity, one of the main challenges concerns their stabilization, with the aim of preserving and tuning their properties. The use of an inorganic support with an extended array to stabilize AuNPs is a well-known strategy. Metal phosphonates, due to their versatility, in terms of crystal structures and functionalities are good candidates as supports for AuNPs. Nevertheless, they have been explored to a limited extent so far. This chapter aims to present the state-of-the-art in this field and to stimulate interest in these promising composite systems.