The synthesis and coordination chemistry of methylene bridge-substituted calix[4]arenes

Abstract

Chapter 1 presents an overview of the history of calix[n]arenes. There is particular focus on calix[4]arene and its conformational properties, as well as modification at the upper-, lower-rim and methylene bridge positions. Molecular magnetism is then discussed with important literature examples described. Finally, the coordination chemistry of metal clusters formed from calix[4]arenes are discussed.

Chapter 2 covers the synthesis and characterisation of a calix[4]arene derivative that has been mono-substituted at all methylene bridge positions with 2-methylfuran groups. The coordination chemistry with 3d, 4f, and 3d-4f ions was then investigated. The clusters isolated from these reactions were analysed by X-ray diffraction studies and their structures compared with those previously obtained within this research group.

Chapter 3 focusses on the further derivatisation of a furan-substituted calix[4]arene in order to synthesise other heterocyclic-containing calix[4]arenes. This work was carried out with a particular emphasis on expanding the library of methylene bridge-substituted calix[4]arenes. The synthesis and characterisation of these compounds are described.

Chapter 4 presents work that was carried out by the candidate on placement at the University of Edinburgh in collaboration with the Lusby group. In this section the pyridyl-substituted calix[4]arene synthesised in Chapter 3 was utilised in cage-forming reactions with a view to forming metal-organic assemblies. The results of which are described in detail with supporting evidence in the form of Diffusion Ordered NMR Spectroscopy studies.

Chapter 5 describes the post-synthetic modification of a [MnIII2MnII2] cluster through the addition of chelating co-ligands. The results are that the ligated solvent molecules of the cluster have been displaced by various co-ligands, resulting in a new family of clusters. X-ray diffraction studies were carried out on the resultant clusters in order to determine the stability of the crystalline material upon removal from the mother liquor.

Chapter 6 presents a summary of the work described in this thesis and future work to be carried out in relation to this project.