Versatility of p-sulfonatocalix[5]arene in building up multicomponent bilayers

The ability of pyridine N-oxide molecules to form host–guest complexes with p-sulfonatocalix-[5]arene was probed and resulted in the formation of europium complexes incorporating 2- or 4-picoline N-oxide, and 4,4′-dipyridine N,N′-dioxide. Relative to lanthanide complexes of p-sulfonatocalix[5]arene incorporating pyridine N-oxide, the presence of a methyl group on the aromatic ring for the picoline N-oxides, or a larger dipyridine dioxide guest dramatically alters the self-assembly, resulting in the formation of three new supramolecular motifs for the calixarene.