Chapter 1 presents a brief introduction to the work discussed in this thesis and provides an overview of relevant compounds discussed in the literature, which have informed the results in chapters 2 – 5. An emphasis is placed on the importance of developing heavy atom free photosensitisers for singlet oxygen (1O2) generation, as alternatives to conventional antibiotics, which is the basis for the work detailed in these studies. There have been a limited number of BODIPYs reported which meet these criteria, leaving their potential somewhat unrealised as antimicrobial photodynamic agents. BODIPYs for use in photocatalytic hydrogen evolution are briefly discussed as to provide a basis for chapter 5’s studies. Chapter 2 explores heavy-atom free anthracene-BODIPY dyads as potential antimicrobial agents, and ability to bind to bovine serum albumin (BSA). A series of time-resolved studies were conducted ranging from the picosecond to microsecond time range to probe the excited state dynamics of the photosensitisers and pathways taken to initiate and propagate ISC. Substitution at the 2 and 6 positions with alkyne linkage and piperazine units was also carried out to tune the anthracene BODIPY dyad for better red-light absorption and biocompatibility. Chapter 3 follows on from the work conduct previously in the group by Cullen et al. by incorporation of BODIPYs into conjugated copolymers with 1,4diethynylbenzene linkers for potential as antimicrobial materials. Differences were observed in the photophysical properties of each polymer family, with the mesosubstituent playing a key role in the excited states populated by the copolymers. Chapter 4 focuses on the impact of extending the π-conjugation of an anthraceneBODIPY dyad about the 2 and 6 position to induce a significant red-shift in its absorption to improve suitability for antimicrobial photodynamic therapy (aPDT). The BODIPY dyad with extended conjugation exhibited long-lived excited states, high singlet oxygen quantum yields and was shown to be potent against Gram-positive bacteria species, even in the case of MRSA strains. Chapter 5’s focus shifts from biological applications, whereby a series of 2,6-iodinated BODIPYs with varying mesosubstituents were evaluated for their photocatalytic potential for hydrogen generation.