Coordination Cages: Beyond The Solution State

Abstract

Metal-organic coordination cages can be assembled from simple building blocks to form a wide range of structure types such as Platonic and Archimedean solids. Such architectures are able to encapsulate a diverse array of molecular guests in the solution state, from both organic and aqueous media. This thesis investigates the application of metal-organic coordination cages in the solid-supported physisorbed and neat liquid states and the host-guest chemistry of the resulting materials. This thesis is divided into three main sections are these are outlined below:

Chapter 1 presents a brief introduction to the history and development of supramolecular chemistry and metal-organic architectures. A particular emphasis is placed on the formation of coordination cages and the factors unpinning their guest encapsulation properties.

Chapter 3, the first research chapter, investigates the adsorption of coordination cages on to alumina supports, via solution depletion, from water and acetonitrile. The adsorbed cages are analysed spectroscopically and their host-guest chemistry is probed via a series of guest displacement experiments under flow conditions. Finally, it is demonstrated that adsorbed cages can be used to store reactive molecular guests for subsequent release and reaction.

Chapter 4, the second research chapter, presents the current progress towards the development of a new generation of porous liquids based on coordination cage scaffolds peripherally-functionalised with polymer chains. The first section explores the use of a coordination cage ion metathesis reaction in the formation of a cage salt. The second section investigates the effect of the peripheral chain length on the thermal properties of the resulting cage materials.