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Self‐Assembly of Tris(2‐ureidobenzyl)amines: A New Type of Capped, Capsule‐Like Dimeric Aggregates Derived from a Highly Flexible Skeleton
Author(s) -
Alajarín Mateo,
Pastor Aurelia,
Orenes RaúlÁngel,
Steed Jonathan W.,
Arakawa Ryuichi
Publication year - 2004
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.200305559
Subject(s) - tris , chemistry , substituent , urea , solvent , crystallography , stereochemistry , organic chemistry , biochemistry
A set of tris(2‐ureidobenzyl)amines 3 was prepared and their dimerization processes thoroughly investigated. In spite of their inherent flexibility, tris(ureas) 3 form dimeric aggregates both in the solid state and in solution. Evidence for the existence of these dimeric species was provided by a combination of techniques (X‐ray analysis, NMR and IR spectroscopy, and ESI‐MS). The association constants and thermodynamic parameters for the dimerization processes of selected tris(ureas) were determined and show that they are enthalpically driven. Heterodimerization experiments in solution reveal a high degree of self‐recognition or narcissistic self‐sorting. On the other hand, desymmetrized tris(ureas) derived from 3 self‐assemble with modest regioselectivities depending on the terminal substituent of every urea functionality.