Pseudorotaxanes based on bambus[6]uril
Markéta Kandrnálová
Bambus[n]urils are new family of macrocyclic anion receptors. They are synthesized by acidic
condensation of 2,4-disubstituted glycolurils and formaldehyde leading to macrocyclic structure with
alternate orientation of glycoluril units which are connected together by one row of methylene
bridges. Methine protons of glycolurils, pointing to the center of cavity, interact with anions and
association constants of complexes are remarkably high in both organic and water solutions.1,2
Only
binding of bambusurils with inorganic anions (from halides, through hexafluorophosphate to
perchlorate) was described until now. Here we are presenting formation of complexes with
dicarboxyiodate salts and their properties. We used dodecabenzylbambus[6]uril and studied its
binding with tetrabutylammonium diacetoxyiodate rod in chloroform. The rod is bound inside the
bambusuril cavity forming type of an inclusion complex known as a pseudorotaxane. We prepared
rods with different terminal groups (stoppers) and found that the bambusuril is capable to slip even
over aromatic substituents. Dendrons were used as a stopper which is bulky enough to mechanically
interlock bambusuril on axle and formation of rotaxane was investigated.
References:
(1) Havel, V.; Sindelar, V. Anion Binding Inside a Bambus[6]Uril Macrocycle in Chloroform.
ChemPlusChem 2015, 80 (11), 1601–1606.
(2) Yawer, M. A.; Havel, V.; Sindelar, V. A Bambusuril Macrocycle That Binds Anions in Water with
High Affinity and Selectivity. Angew. Chem. Int. Ed. 2015, 54 (1), 276–279.