Cyclodextrin–calixarene co-polymers as a new class of nanosponges

Hyper-reticulated co-polymers jointly formed by cyclodextrin and calixarene units, which can be consideredas a new class of nanosponges, were easily obtained by means of a click chemistry approach. In particular, wesucceeded in preparing our materials by exploiting the copper-catalyzed 1,3-dipolar cycloaddition(CuAAC) reaction between heptakis-(6-deoxy)-(6-azido)-β-cyclodextrin and (5,11,17,23-tetra-tert-butyl)-(25,26,27,28-tetra-propargyloxy)-calix-[4]-arene, mixed in different proportions. These materials were fullycharacterized by means of combined FT-IR, thermogravimetric, 13C {1H} CP-MAS NMR and nitrogenadsorption/desorption techniques. In particular, 13C {1H} CP-MAS spectra allowed us to perform aquantitative analysis of the co-polymers obtained. Tests on their possible sequestering abilities towardssome organic molecules, in particular nitroarenes and commercial dyes chosen as suitable pollutants ordrug models, were successfully carried out. Results obtained point out that absorption abilities seemaffected by polymer composition and porosity as well.