Interlocked and transition metal based halogen bonding host systems for anion recognition and sensing

This thesis describes the integration of the halogen bonding iodotriazole motif into a range of interlocked and transition metal based architectures for anion recognition and sensing. Chapter One introduces the field of anion supramolecular chemistry, describing the non-covalent interactions exploited by host structures. In particular, this chapter reviews hydrogen bonding and halogen bonding acyclic, macrocyclic and mechanically interlocked molecules for anion recognition. Chapter Two describes the synthesis of acyclic and interlocked tetra-iodotriazole based receptors. In particular, the preparation of a family of [2]catenanes and [2]rotaxanes via a chloride anion template approach is discussed, followed by an investigation of their anion binding properties determined through 1H NMR titration experiments. Chapter Three presents a new methylene-spaced bis-iodotriazole motif and investigates its ability to complex a range of transition metals for anion recognition and sensing. With the aim of forming a [2]rotaxane via an active metal template method, a range of macrocycles containing the motif are prepared. Towards the construction of a fullerene containing rotaxane, bimetallic C60 fullerene containing halogen bonding and hydrogen bonding anion receptors are prepared and their sensing capabilities investigated via luminescence spectroscopy. Chapter Four incorporates a novel benzimidazole-iodotriazole motif into a naphthalimide based axle containing dynamic [2]rotaxane. The requirement for both benzimidazole axle protonation and the presence of a chloride coordinating anion is demonstrated to be crucial for facilitating macrocycle shuttling translocation along the axle component of the [2]rotaxane. The ability of the motif to coordinate photoactive transition metals is also reported. Chapter Five presents a summary of the major conclusions from the research described throughout the thesis. Chapter Six details the synthetic protocols and characterisation data for each novel compound discussed in the previous chapters. Spectroscopic titration experiment protocols are also outlined.