4,7-Dichloro-1,10-phenanthroline is primarily used as a chelating agent in coordination chemistry, forming stable complexes with various metal ions. These complexes are often employed in catalytic processes, particularly in oxidation reactions, where they enhance efficiency and selectivity. The compound is also utilized in the development of luminescent materials, as it can act as a ligand to create metal complexes with unique photophysical properties, making it valuable in optoelectronic applications. Additionally, it finds use in biochemical research as a tool for studying DNA interactions, where its ability to bind to nucleic acids provides insights into molecular recognition and binding mechanisms.