Used primarily as a key intermediate in the synthesis of functional dyes, especially in the production of cyanine dyes for imaging applications. It plays an important role in the development of photographic sensitizers, where it enhances the light sensitivity of silver halide emulsions. Also utilized in the preparation of near-infrared fluorescent probes for biological labeling and detection due to its favorable photostability and emission properties. Its structure supports conjugation in dye molecules, making it valuable in optoelectronic materials and sensors.