Macrocyclic pacman complexes for secondary coordination sphere control

The work presented in this Thesis describes the design, synthesis and reactivity of a symmetric and various asymmetric Schiff-base macrocycles that are capable of forming a wedge-shaped “Pacman” conformation upon metal binding. Chapter One introduces catalysts for small molecule transformation as well as transition metal complexes of pyrrole-containing macrocycles. Further to this, Pacman systems, including previous work from Love and co-workers, and complexes capable of secondary coordination-sphere control will be discussed. Chapter Two details the design and synthesis of two asymmetric macrocycles that both contain one neutral and one N₄-donor imine-pyrrole binding pocket, H₂LP and H₂LNMe. The synthesis and characterisation of the series of complexes [M(LP)] and [M(LNMe)] (M = Pd, K₂, Co, VCl, TiCl, Mg, Fe and Mn) and their characteristics highlighted, including the formation of a supramolecular cyclic hexamer. Chapter Three presents the modification of the above ligands at the meso-group, the N-substituent and the non-pyrrolic binding pocket to give H2LFP and H₂LFNMe, H₂LNMes and H₂L(NH)NMe respectively. Palladium and cobalt complexes of these macrocycles were prepared and characterised. Chapter Four describes the design and synthesis of the ligand H₄LEt as well as the synthesis and characterisation of tin-alkyl and mononuclear calcium complexes of LEt, as well as the heterobimetallic complexes [SnMe₂(M)(THF)(LEt)] (M = Zn or Fe). The homobimetallic complexes [M₂(LEt)] (M = Co, Mg and NbCl) are also presented along with a magnesium-cubane structure of LEt in which the cubane is encapsulated by two, bowl-shaped macrocycles. Chapter Five provides a summary of the work presented in this thesis. Chapter Six describes the full experimental details and analytical data for all compounds synthesised in this work