Self-assembly of tris(2-ureidobenzyl)amines: a new type of capped, capsule-like dimeric aggregates derived from a highly flexible skeleton.
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.
Alajarín
Mateo
M
Departamento de Química Orgánica, Facultad de Química, Universidad de Murcia, Campus de Espinardo, Murcia-30.100, Spain. alajarin@um.es
Pastor
Aurelia
A
Orenes
Raúl-Angel
RA
Steed
Jonathan W
JW
Arakawa
Ryuichi
R
D001596:Benzylamines / Q000138:chemical synthesis* / Q000737:chemistry; D019281:Dimerization; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013055:Spectrophotometry, Infrared / Q000379:methods
D001596:Benzylamines