Interlocked halogen bonding host systems for anion recognition

This thesis describes the synthesis and anion recognition properties of acyclic and mechanically interlocked anion receptors containing either the 3,5-bis-iodotriazole pyridinium or pyridine-N-oxide motifs. Chapter One introduces the field of supramolecular chemistry, highlighting areas of particula...

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Bibliographic Details
Main Author: Robinson, Sean W.
Other Authors: Beer, Paul D.
Published: University of Oxford 2016
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.728786
Description
Summary:This thesis describes the synthesis and anion recognition properties of acyclic and mechanically interlocked anion receptors containing either the 3,5-bis-iodotriazole pyridinium or pyridine-N-oxide motifs. Chapter One introduces the field of supramolecular chemistry, highlighting areas of particular relevance to this thesis, viz. anion coordination, recognition, templation, halogen bonding and synthesis of interlocked structural frameworks. Chapter Two describes the synthesis of acyclic, [2]catenane and water-soluble [2]rotaxane anion receptors containing the novel 3,5-bis-iodotriazole pyridinium motif and details their anion recognition properties. X-ray crystal structures of the [2]catenane bearing this motif are provided in support of the anion binding results. X-ray Absorption Spectroscopy is used to probe the nature, and quantify the degree of covalency, of halogen-bonding interactions. Chapter Three details further work incorporating the 3,5-bis-iodotriazole pyridinium motif into elaborate symmetric and asymmetric [2]rotaxane anion hosts designed for nitrate binding in competitive aqueous solvent media. Moreover, the synthesis of an analogous water-soluble [2]rotaxane is presented and its anion recognition properties investigated. Chapter Four focuses on the synthesis of acyclic and symmetric interlocked anion receptors bearing the novel neutral 3,5-bis-iodotriazole pyridine-N-oxide motif. The anion recognition properties of these hosts are presented with an emphasis on [2]rotaxane species capable of binding chloride and nitrate in competitive aqueous solvent media. Chapter Five provides a summary of the major conclusions of this thesis. Chapter Six furnishes procedures pertaining to chemicals, instrumentation, data handling and analytical protocols, as well as detailing synthetic methods and characterisation of novel compounds. Chapter Seven provides the references cited within Chapters One to Six. Full crystallographic information and details of molecular modeling experiments are provided in Digital Appendices on an enclosed DVD.