Synthesis of New Hydrophilic Capsules

Abstract

Resorcinarenes hydrogen-bonded supramolecular capsules are well known structures for many applications in host-guest supramolecular chemistry in solution. However, all their features as hexameric capsules are preserved exclusively in non-competitive solvents for H-bonding like chlorinated or aromatic ones. The challenging aim of this thesis consists in the design and synthesis of a water-soluble resorcin[4]arene, followed by preliminary studies on its behaviour water or at least polar protic media. For this purpose, new resorcin[4]arene based compounds were designed bearing a short hydrophobic portion in the external feet, to protect the H-bonds, linked to a polyethyleneglycol (PEG) pendant, to confer water solubility. Several synthetic strategies were carried out due the necessity to favor the obtainement of the correct configuration of the resorcin[4]arene as well as proper solubility in water which is function of the length of the PEG units. The most significant synthetic results were obtained under acidic conditions using a stoichiometric combination of resorcinol ad functionalised aliphatic C6 aldehyde connected with a MPEG750 moiety. Full characterization and investigation of aggregation properties for all compounds were carried out through 1H NMR, 13C NMR, 2D COSY, HSQC and HMBC and diffusion-ordered NMR spectroscopy (DOSY) techniques.