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A Short and efficient syntheses of chiral 2, 2¡¦- bipyridine derivatives by Kröhnke reaction. The bipyridines allow well defined in self- assembly of double stranded helicates by coordinating with silver(¢¹).

This study investigates the self-assembly of ligands consisting of sterically hindered backbones. Ligands synthesised in this study took advantage of the twisted nature of benzil-2,3-dihydrazone brought about by the steric repulsion between two neighbouring phenyl groups. Synthesis of all ligands used a simple imine condensation reaction, where benzil-2,3-dihydrazone was combined with a chosen aromatic aldehyde. Coordination studies were conducted using first row transition metals and described in text are the solid state structures of twelve new discrete supramolecular complexes, characterised by single crystal X-ray crystallography. Chapter 1 outlines an introduction to the topics discussed in this text, while providing examples drawn from literature and nature. Chapter 2 details the modified synthesis of bis-2-pyridyliminohydrazono-1,2-diphenylethane, L1, and the in-depth background of previous studies with the ligand. The complexes of L1 with Mn(II), Fe(II), Co(II), Cu(I) and Zn(II) determined by single X-ray crystallography are presented, noting the structural effects different metal ion sources have upon L1. In chapter 3 the modified synthesis and characterisation of bis-2-imidazolyliminohydrazono-1,2-diphenylethane, L2, is presented. Crystallographically characterised complexes from the combination of L2 with Mn(II), Ni(II), Co(II) and Zn(II) show the formation of interesting topologies which are compared to structures previously determined. Chapter 4 begins with a brief introduction to clusters, followed by the synthesis and characterisation of a recently synthesised ligand, bis-2-salicyliminohydrazono-1,2-diphenylethane, L3,. The formation of a Ni(II) cluster with L3 is further discussed in detail, and outlines the future scope for the work with these ligands. The synthesis and characterisation of L4, and the discussion of mononuclear complex formed between L4 and Cu(II) is also introduced. The chapter concludes with a discussion with the potential future direction of this work with these ligands and their related compounds. Chapter 5 concludes the results and discussion with a brief summary of these results. Chapter 6 outlines the synthesis and characterisation of all ligands and complexes used in this study as well as potential ligands for future studies.

Research Doctorate - Doctor of Philosophy (PhD) / This work presents the development and application of modern data acquisition and analysis techniques for the investigations of equilibrium and kinetic reactions. The analytical technique is known as second order global analysis and a background of this relatively novel approach has been given. The theory behind and characteristics of the computer programs developed analysis as part of this research are described in Chapter Two along with descriptions of the instrumentation and programs developed for the acquisition of both potentiometric and spectrophotometric data. Applications of the developed programs include a potentiometric and spectrophotometric study of the protonation and stability equilibria of a series of polydentate N-donor ligands, as detailed in Chapter Three. The combination of potentiometric and spectrophotometric analysis has been shown to be a powerful analytical tool. Spectrophotometric titrations were also combined with fast stop-flow experiments in order to elucidate the complex reaction mechanisms associated with helicating ligands. The helication of the ligand ‘PepdaH₂’ with copper(II) and nickel(II) is examined in Chapter Four, along with discussions concerning the ability to induce chirality in the helicates from the addition of a chiral counter ion. Investigations into chirality were further continued in Chapter Five where the stereoselectivity of a benzimidazole-based ligand was investigated with circular dichroism titrations. The synthesis and characterisation of the benzimidazole-based ligands are provided, including a study of the ability of the ligands to form higher order complexes as investigated using electrospray mass spectroscopy. Chapter Six provides an in-depth discussion concerning the use of combined glass hydrogen selective electrodes for the determination of equilibrium constants, as this was a major focus of this research. Different calibration techniques are discussed and a description of the internal calibration technique developed is provided along with examples of the advantages of performing internal calibration of the electrode.

Dans un premier temps, ce travail décrit la méthodologie de synthèse vers de nouveaux coilants bipyridines-bis-α-cyclodextrines comportant deux ou trois unités bipyridines pour la réalisation de systèmes coordinants tétra- ou octaédriques singuliers. La réactivité des différentes étapes a été étudiée et des molécules clés de la synthèse totale des ces systèmes ont été synthétisées grâce à des réactifs ou réactions issus du laboratoire. Dans un deuxième temps, la synthèse d'un nouveau podant tris-bipyridines-α-cyclodextrine a également été réalisée et ses propriétés de complexation avec les cations de transition ont été étudiées par spectroscopie UV-visible et dichroïsme circulaire. La géométrie hélicoïdale fortement chirale a également été résolue dans le cas de certains complexes de ce podant avec des métaux de transition de dureté intermédiaire / Firstly, this work describes the synthesis methodology toward new bipyridines-bis-α-cyclodextrins coilants with two or three bipyridine units for the achievement of tetra- or octahedral coordinant systems. The reactivity has been studied and key molecules have been synthesisedthanks to our laboratory's methodologies. Sedondly, the synthesis of a new tris-bipyridines-α-cyclodextrin podand has also been performed and its complexation properties with transition cations have been studied by UV-visible spectroscopy and circular dichroism. The highly chiral helix geometry has also been resolved in the case of some metal podendates with borderline transition metals

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