Nitric oxide has been shown in the recent past to have an important role in many biological systems, including an essential role in neurotransmission, blood clotting, and in combating tumour cells and intracellular parasites. This thesis investigates the photochemistry of a series of compounds containing NO as a ligand. The aim of this work is to investigate the possibility that NO could be released under photochemical conditions at specific biological sites, thus providing a novel means of location specific therapy. Chapter 1 is a general overview of the history of organometallic chemistry, including a description of the current bonding models in the type of complexes under investigation. This chapter also includes a literature survey of different types of organometallic compounds containing NO ligands, their chemistry and photochemistry. Chapter 2 describes the photochemistry of compounds of the type (r|3-allyl) Fe (CO)2NO, and (tv-2-chloroallyI) Fe (CO^NO. Ultraviolet/visible monitored flash-photolysis studies and infrared monitored steady state photolysis were used to identify the primary photo-process, namely CO-loss. Matrix isolation was also used to investigate the photochemistry of (r|3-allyl) Fe (CO)2NO and to characterise the primary photoproducts. The photochemistry of (t|3- allyl) Fe CO(NO)PPh3 and (q3-allyl) Fe (PPh^NO was also investigated. No evidence for loss of NO was observed with these systems however. The photochemistry of Fe(PPh3)2(NO)2 is also described. Chapter 3 contains the experimental procedures and techniques used in the synthesis and the analysis of the compounds used in this work.