| Abstract [eng] |
Supramolecular capsules are receiving increasing attention because of their uses in molecular recognition, transportation and catalysis. Formation of supramolecular capsules is driven by non-covalent iteractions such as hydrogen and coordination bonding, hydrophobic and π-π interactions, Van der Waals forces. Due to these interactions, supramolecular capsules exhibit new features, non-charachteristic to compounds formed covalently, and give insight into complexation phenomena. Directionality and specificity makes hydrogen bonding especially popular in the field of supramolecular chemistry. Most structures utilize multiple hydrogen bonding. In order to unambiguously drive formation of desired structures, preorganization of hydrogen bonding motives is achieved through synthesis of geometrically fixed monomers. In this work, conformationally labile monomers are chosen to form supramolecular capsules. In effort to achieve this goal, tripodal monomers consisting of benzentricarboxylic acid core, flexible alkyl linkers and three 4 H-bonding uridopyrimidinone (UPy) units were synthesized. Importance of alkyl side-chains for monomer solubility in nonpolar media was noticed. Two of the synthesized monomers showed formation of supramolecular aggregates which structures were identified by NMR spectrocopy and computer model. Also, we have demonstrated selective formation of heterodimeric capsule. Stability of capsular aggregates was evaluated with competing H-bond forming diamidonaphtyridine (DAN) and also with increase in monomer concentration. Supramolecular capsules can be further stabilized through formation of extra hydrogen bonds between oxygen atom of UPy in one monomer and hydrogen of amide in other and exibit properties of supramolecular buffer. |
