Novel pillar[5]arene and oxacalix[4]arene derivatives for the recognition and sensing of nitrogen-containing guests

This PhD thesis is composed of two parts describing two different families of macrocycles. The first part is focused on a recently reported class of macrocycles known as the pillar[n]arenes. In this part the synthesis, functionalization and properties, in particular of the pillar[5]arene, are reported. In this part of the thesis a newly synthesized pillar[5]arene fluorescent chemosensors is reported. The emission properties of this compound originate from two dansyl groups linked to the pillararene on the opposite rims of the cavity. The sensing properties of such receptor were tested against a paraquat derivative. Herein, the synthesis and characterization of a new pillar[5]arene dicarboxylic acid pseudo[1]catenane is reported. This compound was obtained as two different diastereomers. It features an ancillary cyclic chain that, depending on the solvent, may be self-included (inconformation) or lie outside (out-conformation) the cavity of the macrocycle. The second part of the Thesis is focused on a calixarene-related class of macrocycles: the oxacalix[n]arene. A new ionizable water soluble oxacalix[4]arene is reported: this compound may exist in seven different protonation states, from dianionic to tetracationic.A comprehensive study by means of NMR spectroscopy, absorption spectroscopy and DFT-calculation allowed us to unravel the multiple equilibria regulating the distribution of protonated macrocycles over a wide pH range.