Carbon monoxide (CO) is now well established as one of the signaling molecules in higher organisms, including humans. Due to its physiological roles, CO is now accepted as a potential therapeutic agent. The use of CO gas has been studied in multiple clinical trials. Vasodilation, anti-inflammatory, anti-apoptotic, anti-proliferative and cytoprotective effects are just a few of the pharmacological actions attributed to CO gas in various models of diseases. Use of inhaled CO gas as a therapeutic has many limitations which necessitate the development of a new approach for CO delivery. In order to handle CO safely, compounds that release CO (CO-releasing molecules, CORMs) have been developed. CORMs that release CO only when triggered, and with the ability to target certain tissue sites, are of particular interest. Our lab is developing molecules that release CO only when illuminated with visible light (photoCORMs). These photoCORMs are based on a motif found in naturally-occurring flavonols, which are chemical compounds found in wide variety of foods including fruits, vegetables, tea and dark chocolate. The research presented in this dissertation outlines the results of studies on extended flavonols as CO release agents. The specific studies described herein focus on understanding visible light-induced CO-releasing flavonols in terms of their: a) structure/reactivity relationships, especially in biological environments; b) interactions with metal ions and proteins; c) reaction pathway of CO release; and d) their properties when combined with a CO-sensing motif.