Synthesis and characterization of electron deficient heterocycles as building blocks for electronic materials

This thesis describes the synthesis of a new electropolymerizable viologen derivative. A reasonably high-yielding route is reported, and a preliminary investigation of its polymerisation is described. The viologen and its precursors were examined by 1H NMR, MS, IR and elemental analysis. The energies of the band gap for the materials have been calculated using UV-vis spectroscopy, and cyclic voltammetry was also used to estimate the oxidation and the reduction potentials and to calculate the HOMO and LUMO energies. Theoretical calculations were performed using DFT. The attempted synthesis of a new flavin-functionalised phenanthroline derivative is described. Unfortunately, the protocol used failed to provide the desired compounds.

Diketopyrrolopyrrole derivatives for bulk heterojunction and dye sensitised solar cells

This thesis describes the synthesis and characterisation of a series of molecules for use in bulk heterojunction and dye sensitised solar cells. The target molecules were based on a central diketopyrrolopyrrole subunit. Molecules based on diketopyrrolopyrrole have a conjugated structure, allowing for π-π interaction. Diketopyrrolopyrrole molecules also have relatively low lying HOMO and LUMO levels and high absorption coefficients and exhibit efficient charge transport properties. Furthermore, their electron withdrawing properties have warranted their use as promising organic photovoltaic materials. A number of molecules were successfully synthesised and sent to collaborators for testing in organic photovoltaic devices and development of this series of molecules continues to be of interest within the research group.