4-bromo-1,10-phenanthroline is primarily used in coordination chemistry and as a ligand in the synthesis of metal complexes. It is particularly valuable in the development of luminescent materials and sensors due to its ability to form stable complexes with transition metals. This compound is also employed in the study of electron transfer processes and in the design of catalysts for organic reactions. Additionally, it finds applications in the field of supramolecular chemistry, where it is used to create intricate molecular architectures. Its bromine substituent allows for further functionalization, making it a versatile building block in synthetic chemistry.