Used as an intermediate in the synthesis of fluorescent dyes and optical brighteners due to its ability to form complexes with metal ions that exhibit strong luminescence. Commonly employed in the development of chemosensors for detecting cations such as aluminum, zinc, and iron in environmental and biological samples. Its structure supports intramolecular charge transfer, making it valuable in the design of organic semiconductors and nonlinear optical materials. Also utilized in the preparation of naphthoxanthene dyes for laser applications and in photostable imaging agents for biochemistry.