Carbon-rich coordination cages

Abstract

This thesis consists of five chapters describing the synthesis and host-guest binding studies of various carbon-rich metallosupramolecular cages. Chapter 1 provides an introduction of the field of metallosupramolecular chemistry, describing the three main synthetic methods of metallosupramolecular cage formation (symmetry interaction, directional bonding, and weak-link approaches) along with examples of host-guest binding interactions and applications of various cage systems. Also included in Chapter 1 is an overview of PAHs, focusing on the synthesis and applications of assorted HBCs. Chapter 2 describes the synthesis of a number of quadruply stranded M2L4 cage architectures, with phenylene and anthracenylene linker units. The effects of the two linker units with differing surface area and bulk were studied on two aspects: on host-guest binding interactions with a number of guest molecules, and the controlled formation of heteroleptic M2AnB4-n cage systems. Chapter 3 describes the formation of two octahedral M6L8 cages, consisting of either ethylene or phenylene linker units. The two linkers units differ in length and surface area, leading to different cavity and portal sizes, and their effects on host-guest binding interactions with a range of guest molecules were investigated. Chapter 4 describes the synthesis of two distinct cage architectures, the semi-octahedral M6L4 and the triangular prismatic M6L2 cages, utilising the same trigonal benzene core ligand with 4-pyridyl coordinating units and either the cis-capped Pd(II) or the di-Ru(II) clip units. The benzene core M6L4 and M6L2 cage architectures were synthesised as a smaller, less synthetically challenging analogues of the HBC core cage architectures to be attempted later. Chapter 5 describes the synthesis of four generations of HBC ligands and the attempted synthesis of the octahedral M6L8, semi-octahedral M6L4, and triangular prismatic M6L2 cage architectures with the HBC ligands.