Self-aggregated assembled with pre-programmed properties: nanoclusters and functional switching small molecules.

The understanding of the role of the self-assembly mechanisms is crucial to realize molecularly precise self-organized systems at the nanoscale with a well-defined architectures and preprogrammed electronics properties. The PhD activities focused on the study of self-assembly mechanisms of model systems at liquid–solid interfaces forming meso- and macro-scopic ordered structures mainly investigated with advanced Scanning Probe Microscopies. Two building blocks have been studied as ideal chemical models: i) synthesized metal-organic nanoclusters formed by 44 silver atoms coated by a monolayer of 30 thiol ligands (a.k.a. IBAN, intensely and broadly absorbing nanoparticles), and ii) commercial azobenzene molecules (Disperse orange 3 and Acid yellow 9). IBANs fully monodispersed nanoparticles stable in solution used as prototype system to produce high quality macroscopic crystals. Conversely, commercially available on Sigma Aldrich, azobenzene molecules are used to produce functional architectures using scalable approaches. In particular, the integration of molecular switches with inorganic surfaces has recently shown an increasing interest to produce novel hybrid multifunctional materials. IBANs can form 2D and 3D structures with different properties and crystals order while azobenzenes form self-assembled monolayers (SAMs). By chemical approach and solvent vapour annealing, a simple but powerful technique developed in our group, we could tune the morphology and the physico-chemical properties of such self-assembled structures with the aim of producing smart hybrid materials.