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Counterion‐Dependent Proton‐Driven Self‐Assembly of Linear Supramolecular Oligomers Based on Amino‐Calix[5]arene Building Blocks
Author(s) -
Pappalardo Sebastiano,
Villari Valentina,
Slovak Sarit,
Cohen Yoram,
Gattuso Giuseppe,
Notti Anna,
Pappalardo Andrea,
Pisagatti Ilenia,
Parisi Melchiorre F.
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200601785
Subject(s) - counterion , oligomer , supramolecular chemistry , monomer , chemistry , moiety , solvation , polymer chemistry , intermolecular force , self assembly , calixarene , crystallography , ion , stereochemistry , molecule , organic chemistry , polymer , crystal structure
Self‐assembly of a calix[5]arene bearing a 12‐aminododecyl pendant group on the lower rim into supramolecular oligomers through intermolecular iterative inclusion events is readily triggered by contact with acid solutions and is reversed to the amino monomer precursor by treatment with a base. 1 H NMR data are consistent with the formation of head‐to‐tail assemblies derived from endo ‐cavity inclusion of the alkylammonium moiety. Diffusion NMR and light‐scattering studies provide evidence for the presence of oligomers in solution and show that different counterions and concentrations result in different oligomer sizes, whereas ESI‐MS and SEM investigations, respectively, indicate that self‐assembly also takes place in the gas phase and in the solid state. The growth of these supramolecular oligomers is concentration‐dependent; however, as a consequence of the saline nature of the monomer, it also shows a distinct counterion‐dependence owing to ion‐pairing/solvation effects.