Bambusurils in supramolecular chemistry
Václav Havel
Bambusurils (BU) are macrocyclic molecules consisting of glycoluril units connected
by one row of methylene bridges. They are formed under acidic conditions from
formaldehyde and 2,4-disubstituted glycoluril in the presence of template.1
The six membered macrocycles are potent anion receptors in both organic and
aqueous solutions. They form stable inclusion complexes with inorganic as well as
organic anions, provided that the negatively charged guest has sufficiently small size
to fit in the flexible BU cavity.
RR RR
RR
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O
O
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N
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R RR
R
R R
N N
N N
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N N
N N
N N
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R:
Figure 1. Dodecabenzylbambus[6]uril used in the studies.
Two supramolecular studies utilizing BU will be presented:
In the first study an interesting phenomena was observed in chloroform where the
stoichiometry of complexes with organic anions can be influenced by the presence or
absence of water molecules. Complexes mediated by water molecules are important
in natural systems and this supramolecular structure represents a novel example of
an artificial system.2
In the second study an application of BU as an anion receptor will be presented.
Based on its selective response towards various anions as detected by NMR
spectroscopy we were able qualitatively and quantitatively analyze complex mixtures
of NMR inactive anions.3
1. J. Svec, M. Necas and V. Sindelar, Angew. Chem., Int. Ed., 2010, 49, 2378–2381.
2. V. Havel, V. Šindelář, M. Nečas and A. E. Kaifer, Chem. Commun. 2014, 50, 1372–1374.
3. V. Havel, M. A. Yawer and V. Šindelář, Chem. Commun., 2015, DOI: 10.1039/C4CC10108A.