Synthesis of new building blocks for the construction of self-assembled molecular architectures

Moving within the supramolecular area, this PhD thesis develops four main themes. The study of formation of supramolecular architectures by use of different building blocks is reported. In chapter 1 metal-salophen complexes, which are largely exploited in supramolecular chemistry, will be introduced. These ligands are Shiff bases which can coordinate different metals, tuning in this way the properties of the complex. In the first chapter their potentiality to behave as building blocks for the generation of supramolecular architectutes is explored. The family of bis-urea derived molecules represents another example of building blocks frequently used in supramolecular chemistry. These molecules are self organised through hydrogen bonds in supramolecular polymeric tubular gels, and guest molecules can be hosted within the tubes . The functionalisation of the basic structure of urea derived aompounds and the studies of their properties are described in chapter 2. Metal-salophen derivatives can have interesting application in the field of material chemistry. Macrocyclic structures incorporating such units have been used to generate interpenetrated systems like pseudo-rotaxanes and [2]rotaxanes. The force that keeps together the two units of the system is an acid-base Lewis interaction. These structures can work as molecular machines, giving response to an external stimuli. In chapter 3 different approaches to the synthesis of such systems are described. For the construction of [2]-rotaxane systems a series of three new macrocycles of different dimension were synthesized. Chapter 4 deals with preliminary experiments focused on their potential behaviour as ion-pair receptors.