Uncharged water-soluble amide derivatives of pillar[5]arene: synthesis and supramolecular self-assembly with tetrazole-containing polymers

New uncharged water-soluble pillar[5]arene derivatives bearing 2-hydroxyethylamide and 2-hydroxypropylamide moieties have been for the fi rst time synthesized via aminolysis. A detailed analysis performed for the spectral data (UV, IR; and 1H, 13C, NOESY, and HSQC NMR) allowed us to determine the spatial structure of the synthesized macrocycles. Aggregation properties of the obtained compounds with water-soluble tetrazole-containing polymers, viz. poly-5-vinyltetrazole (PVT) and polyvinyl(tetrazolyl)ethyl ether (PVTE), were evaluated. Pillar[5]-arene containing 2-hydroxyethylamide moieties formed monodisperse nanoscale aggregates with an average hydrodynamic diameter of 117 nm in the presence of PVTE in aqueous solution. The morphology of resulting particles was determined by scanning electron microscopy.