Dynamic Covalent Capsules based on Calix[4]pyrrole Scaffolds

Identificador:  TDX:4218

Handle: https://hdl.handle.net/20.500.11797/TDX4218

Autors:  Mirabella, Chiara Francesca Maria

Resum:
This thesis describes the assembly of tetra- and octa-imine based cages and capsules with polar inner cavities. We investigate the template-assisted dynamic self-assembly of these cages as well as the self-assembly in the absence of a templating guest, in CDCl3 or CDCl3:CD3CN mixtures. The capsules’ and cages’ backbone is based on calix[4] pyrrole units, which are known to bind polar neutral or charged molecules such as N-oxides and anions. For the cages and capsules assembled in the absence of a templating guest, we describe the 1H NMR binding studies towards a series of monotopic and ditopic N- oxides with different chemical structure, length and size. We describe the different kinetic of encapsulation of the guests in CDCl3 and CDCl3:CD3CN mixtures. We report the effect of the presence of a polar competing solvent (i.e. CD3CN) on the rate of guest uptake. Finally, we take advantage of the large cavity of the assembled octa-imine capsules and their post-assembly modified derivatives (i.e. octa-amine capsule) to study their use as supramolecular nanoreactors to mediate chemical reactions. More specifically, we study the role of the cavity in accelerating the rate of the Huisgen azide-alkyne 1,3-dipolar cycloaddition reaction between pyridine N-oxides endowed with terminal alkyne and azide functionalities.