Towards the Living Supramolecular Polymerisation of Tetra(aniline)-Functionalised Perylene Diimides

Student thesis: Master's ThesisMaster of Science (MSc)

Abstract

Perylene diimides (PDIs) provide a promising platform to create functionalised supramolecular polymers with controlled morphology and optoelectronic properties. The imide substitution of PDIs can finely tune the morphology and mode of growth of PDI supramolecular polymers, whilst the addition of functional moieties at the imide position yields supramolecular materials with new functionalities. Meanwhile, two major challenges in the field of poly(aniline)-based nanomaterials - improving their conductivity and stimuli response - can be addressed by finely controlling their nanostructure. This project envisions that incorporation of poly(anilines) into the imide substituents of PDIs will create controlled, functional supramolecular polymers to solve these challenges and open up new horizons in the field of multifunctional supramolecular polymers and devices.

In this thesis, the rational design, synthesis and supramolecular polymerisation of a tetra(aniline) functionalised PDI, PDI-2-TANI, is reported. Comprehensive synthetic pathways were trialled and optimised to create PDI-2-TANI through a series of heterocoupling reactions. The modularity of these coupling reactions allowed PDI-2-TANI to be synthesised through several different routes and provides a flexible framework to create other tetra(aniline)-substituted PDIs for future research.

The supramolecular polymerisation of PDI-2-TANI was studied via transmission electron microscopy and ultraviolet-visible spectroscopy. Thermally self-seeded aggregates of PDI-2-TANI, prepared via heating and cooling, consisted of ordered fibre bundles, with each fibre corresponding to an H-aggregated supramolecular polymer. The low dispersity of these fibres indicated that PDI-2-TANI underwent a living supramolecular polymerisation. Seeded growth experiments partially confirmed this, but a cooperative growth mechanism was not established via ultraviolet-visible spectroscopy. The PDI-2-TANI polymers were found to be out-of-equilibrium self-assemblies, requiring high temperatures to activate the unimer, whereupon it polymerised upon cooling. The discovery of this out-of-equilibrium behaviour yields a promising route to refine spectroscopic and seeded growth experiments and establish thermal self-seeding as a new method to perform living supramolecular polymerisations.
Date of Award26 Nov 2020
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorAvinash J Patil (Supervisor) & Charl F J Faul (Supervisor)

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