Tetrazine-norbornene cycloadditions in macromolecular synthesis and functionalisation

Abstract

This thesis explores the use of the tetrazine–norbornene inverse electron demand Diels-Alder cycloaddition reaction in polymer and materials science. Chapter 1 gives an introduction to the main concepts and techniques used throughout the thesis. Chapter 2 applies the tetrazine–norbornene reaction to polymer endfunctionalisation and polymer–polymer coupling, in both organic media and water, and establishes the methods (UV/vis and 1H NMR spectroscopies) for monitoring the coupling reaction. Chapter 3 applies the reaction to the modification of a self-assembled polymer micelle and demonstrates its use in tandem with the coppercatalysed azide–alkyne click reaction. The synthesis of an amphiphile bearing both norbornene and alkyne groups is described, the amphiphile is self-assembled and a one-pot dual functionalisation of both the core and shell carried out. Chapter 4 describes the formation and analysis by a variety of methods of sub-20 nm sized polystyrene nanoparticles through the single chain collapse of a norbornene-decorated polymer, ligated with a bisfunctional tetrazine. Chapter 5 discusses attempts to further expand the use of the reaction of tetrazines to polymers bearing pendent alkene groups. The synthesis and characterisation of such polymers is detailed, and attempts to functionalise with a variety of tetrazines described