Used as a key intermediate in the synthesis of fluorescent dyes and optical brighteners due to its strong electron-withdrawing anhydride group and heavy atom effect from bromine, enhancing intersystem crossing in photophysical applications. Commonly employed in the preparation of naphthalimide-based fluorescent probes for bioimaging and sensor technologies, where it helps detect metal ions, pH changes, or biomolecules in solution. Its planar aromatic structure allows for strong π-stacking, making it useful in organic semiconductors and optoelectronic materials. Also serves as a building block in the development of photoactive polymers and dyes for dye-sensitized solar cells.