MESA+ Institute for Nanotechnology

The subjects of this thesis are synthesis, characterization and investigation of the binding properties of supramolecular capsules based on ionic interactions.

In Chapter 2 an overview of molecular containers i.e. capsules, cages and supramolecular clusters obtained via covalent and noncovalent synthesis is given.

Chapter 3 reports on the synthesis of oppositely charged calix[4]arenes as building blocks for bimolecular capsules based on ionic interactions in methanol and methanol/water solutions.

In Chapter 4 a detailed study of the influence of the side chain length of differently substituted tetraamidinium calix[4]arenes on the geometry and thermodynamics of the self-assembled molecular capsules is described. The encapsulation properties of one molecular capsule in methanol are investigated. Moreover, this chapter reports on structural variations within one of the building blocks to achieve water-solubility of the molecular capsule.

Chapter 5 reports on the formation of molecular capsules made soluble in aqueous solution by the introduction of amino acids in one of the building blocks. A docking procedure has been used to identify possible guest molecules. The binding properties towards both charged and neutral molecules in aqueous solution are discussed.

Chapter 6 describes how the combination of preorganization and of an array of alternating charges can be applied to achieve a multicomponent molecular capsule based on the self-assembly of six components.

The possibility of building a molecular capsule at a surface is the topic of Chapter 7. A multistep approach for this synthesis is reported which involves the attachment of one building block to a “molecular printboard” followed by the self-assembly of the second component at the interface.