Heteroditopic Calix[4]arene Based Receptors for Ion-Pair Recognition and Mechanical Bond Assembly

Thesis

This thesis investigates the design, synthesis and binding properties of novel calix[4]arene based heteroditopic receptors and interlocked structures.

Chapter 1 introduces the field of supramolecular chemistry. The areas of host-guest chemistry and self-assembly are introduced, with a particular emphasis on strategies for designing receptors for ions and synthesising interlocked structures.

Chapter 2 details the synthesis and binding properties of calix[4]arene based ion-pair receptors. These receptors show cooperative AND ion-pair recognition, where the receptors show little affinity for the 'free' ions but enhanced binding of the ion-pair. The extension of this work to the synthesis of their cryptand analogues is also explored. Finally, efforts towards preparing calix[4]arene based zinc Schiff base anion receptors is reported.

Chapter 3 describes the synthesis of the first calix[4]arene based rotaxane host systems for anions using a new ion-pair templation strategy. NMR spectroscopy and X-ray crystallography demonstrate the successful interlocking of the macrocycle and axle components in the rotaxane structures. Anion binding studies reveal the importance of preorganisation of the host binding cavity on anion binding. The synthesis of rotaxanes using a stoppering approach and catenanes using a ring closing metathesis clipping strategy is also investigated.

Chapter 4 investigates the use of copper catalysed coupling reactions, such as Eglinton coupling and click chemistry, in the preparation of interlocked structures. The synthesis and anion binding properties of a novel catenane are described. Efforts towards the first anion templated synthesis of rotaxanes by slippage and kinetic slippage studies are also reported.

Chapter 5 reports the experimental procedures and characterisation details of the compounds synthesised in this thesis.

Chapter 6 gives supplementary information about titration protocols, kinetic experiments and X-ray crystal structures.

Authors: McConnell, A

• DOI: 10.5287/ora-5rdv2gabk
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford