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.
Supramolecular AA/BB-type oligomer formation from a heterotetratopic bis-calix[5]arene monomer and octanediyldiammonium dichloride
GARGIULLI, Claudia;GATTUSO, Giuseppe;NOTTI, Anna;PARISI, Melchiorre
2011-01-01
Abstract
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.Pubblicazioni consigliate
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