Molecular and supramolecular behaviour of tubular macrocycles

The topics covered in this PhD thesis concern the synthesis, the structural features and the molecular and supramolecular properties of tubular-shaped compounds, more specifically it focuses on macrocycles of the calix[4]arene and pillar[n]arene families. After an introduction on the general aspects of supramolecular chemistry, some representative properties of the most common families of macrocyclic compounds are briefly surveyed (Chapter 1). In Chapter 2, the synthesis of a new tubular derivative (UC4T) belonging to the calixarene sub-family of calix[4]tubes is reported and its structural properties are discussed both in solution (NMR studies) and in the solid state (X-ray crystal analysis) in relation to its propensity to bind metal ions and form polycapsular assemblies. Chapter 3 explores the use of suitably functionalised pillar[5]arenes (QP5C4/QP5C10) as potential precursors for the formation of self-diagnosing smart polymers by way of exploiting the optical response generated by a supramolecular inclusion complex with a fluorophore derivative. The chapter also discusses the formation of a pseudo[1]rotaxane species and its solvent-dependent properties. Chapter 4 deals with the formation of host-guest complexes in aqueous media. It describes the synthesis of a novel water-soluble pillar[6]arene (WSP6) that has been shown to interact with two model drugs, in one case to form surfaces with antibacterial and anti-adhesive properties, and in the other acting as a cargo molecule for drug release from a discrete system.