Synthesis of C 3 -symmetric tri(alkylamino) guests and their interaction with cyclodextrins
The synthesis of a series of star-shaped C 3 -symmetric amines and their inclusion complexation properties toward α-, β-, γ-cyclodextrins and their permethylated derivatives has been described. The star molecules comprise of 1,3,5-trisubstited benzene core and the points formed by (alkylamino)methyl or 4-((alkylamino)methyl)phenyl groups. The modes of host–guest interaction were studied by UV–Vis spectroscopy, ITC, 1H NMR and 2D-NMR (NOESY). It was found that star molecules containing (tert-butylamino)methyl, (adamantan-1-ylamino)methyl, 4-((isopropylamino)methyl)phenyl, 4-((tert-butylamino)methyl)phenyl and protonated 4-((adamantan-1-ylamino)methyl)phenyl points form strong host–guest complexes with β-cyclodextrin. It was also proved that the largest C 3 -symmetric guest can form complexes with β-cyclodextrin with stoichiometry 3 which is required for construction of dendrimer supramolecular structures. None of the investigated amines forms a strong complex with permethylated cyclodextrins.
KeywordsCyclodextrin Supramolecular interactions C3-symmetric guests Inclusion complexes
This work was supported by the Ministry of Education, Youth, and Sports of the Czech Republic (project No. MSM0021620857) and Grant Agency of the Czech Republic (project No. 13-01440S). Help of Dr. S. Filippov with ITC measurements is appreciated.
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