Supramolecular AA/BB-type oligomer formation from a heterotetratopic bis-calix[5]arene monomer and octanediyldiammonium dichloride

A novel bis-calix[5]arene (1) with divergent cavities was prepared in four steps starting from p-methylcalix[5]arene. This molecule is composed of two calix[5]-bis-crown-3 units held together, via their narrow rims, by a N,N ''-1,4-phenylene-bis[N'-(2-ethenyloxyethyl)]diureido bridging moiety. Owing to the anion-binding ability of the ureido moieties embedded in its framework, bis-calix[5]arene 1 acts as a heterotetratopic monomer and, in the presence of 1,8-octanediyldiammonium dichloride, self-assembles into AA/BB-type polycapsular oligomers. Extensive H-1 NMR investigations have demonstrated that the nature and stoichiometry of these supramolecular oligomers are strongly dependent on the concentration and the ratio of the two monomers. (C) 2011 Elsevier Ltd. All rights reserved.