| Summary: | This thesis describes the synthesis of three series of perylene diimides (PDIs) by functionalisation at all four possible regions of the molecule. The synthesised compounds were then probed by optical, electrochemical and photophysical methods in order to fully elucidate their properties.
Chapter 1 gives an overview of the structure, synthesis, properties and applications of PDIs and introduces the main topics investigated in this thesis.
Chapter 2 describes the synthesis of two of the first examples of PDIs with an absorption maximum in the near infrared. This was achieved by functionalisation of the bay area with a secondary amine followed by thionation of the imide carbonyls. One of the synthesised PDIs displays a highly unusual black colour, demonstrating absorption of light across an impressive range of the sun’s emission spectrum, suggesting excellent potential for incorporation into light harvesting devices.
Chapter 3 details the synthesis of seven multichromophoric systems composed of PDIs and boron dipyrromethenes (BODIPYs). The number and position of the BODIPYs is varied along with the structure of the BODIPYs themselves by addition of methyl- and catecholate groups. The absorption and emission properties of the systems were investigated in order to elucidate any energy or electron transfer processes occurring. Energy transfer results in fluorescence solely from the PDI chromophore, rather than the BODIPY, whilst electron transfer was found to quench emission. Communication across the core of the PDI was observed between the BODIPY moieties, shown by cyclic voltammetry, whilst spectroelectrochemical methods demonstrated the effects of oxidation and reduction upon the absorption of the molecules.
Chapter 4 reports on the synthesis of a pair of PDIs symmetrically and asymmetrically substituted with a platinum acetylide complex. Transient absorption spectroscopy and singlet oxygen generation measurements confirmed the formation of the triplet excited state of the PDI, due to the ‘heavy atom’ effect, induced by the presence of the platinum complex covalently bound to the PDI.
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