Evidence of a self-inclusion phenomenon for a new class of mono-substituted alkylammonium-beta-cyclodextrins.
A new class of mono-substituted N-alkyl-N,N-dimethylammonium-beta-cyclodextrins has been synthesized in a three step procedure from the native beta-cyclodextrin. The structural analysis of these compounds undertaken by combined use of 1D and 2D NMR spectra indicate that the two methyl groups bound on the nitrogen are magnetically inequivalent due to a self-inclusion phenomenon of the alkyl chain inside the CD cavity. A variable-temperature 1H NMR study showed that these mono-substituted CD derivatives formed temperature-independent intramolecular complexes with their own alkylammonium substituent. The strength of the interaction between the alkyl moiety and the cyclodextrin cavity has been evaluated by a competitive method using an adamantane derivative. Finally, surface tension measurements demonstrated the surface active character of these compounds and confirmed their self-inclusion ability.
Binkowski
Cécile
C
Laboratoire de Physico-chimie des Interfaces et Applications-FRE CNRS 2485, Faculte Jean Perrin, Universite d'Artois, rue Jean Souvraz, S. P. 18, 62307 Lens Cedex, France.
Hapiot
Frédéric
F
Lequart
Vincent
V
Martin
Patrick
P
Monflier
Eric
E
D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000138:chemical synthesis / Q000737:chemistry*
D000644:Quaternary Ammonium Compounds; D047392:beta-Cyclodextrins