Dynamic Nanomaterials with Functional Properties

In this Thesis, molecular dynamics simulations and enhanced sampling techniques were employed to investigate the factors underlying the functional properties of gold nanoparticles coated with self-assembled monolayers of surface-bound organic ligands. Although the distinctive physicochemical properties of nanometer-sized gold colloids are well established, these systems remain the subject of active and growing research. In recent years, attention has progressively shifted from the intrinsic properties of the gold core to the versatility and tunability of the surrounding organic shell. Non-covalent interactions between confined ligands, play a central role in defining the emergent properties of these hybrid inorganic–organic nanomaterials. By carefully tuning ligand’s chemistry, monolayer structure and functionality can be precisely tailored, unlocking a wide range of potential applications. In this Thesis, after introductory Chapters addressing the state of the art and the computational methods employed, we investigated and rationalized the properties of different kinds of functionalized nanoparticles. In Chapter 3, we demonstrated how ligands bearing a built-in photoswitch can completely suppress the catalytic activity of a metal complex through steric effects. Chapter 4 focused on the catalytic acceleration achieved via substrate proximity promoted by recognition-enabled ligands engaging non-covalent interactions with the substrates. The results of Chapter 5 revealed how different fluorinated amphiphilic ligands influence both monolayer structure and potential application in 19F-MRI and drug delivery. Finally, Chapter 6 and 7 investigated the interactions between catalytic supramolecular structures (metal-organic cages and macrocycles, respectively) and monolayers, aiming to combine their properties. Overall, the atomistic insights obtained from molecular dynamics simulations provided a comprehensive picture of the designing principles of this class of nanomaterials.