Used in organic synthesis, particularly in the preparation of fluorescent dyes and photoactive compounds. Its rigid julolidine structure enhances electron donation, making it valuable in developing dyes for laser applications, sensors, and bioimaging. Commonly employed in the synthesis of cyanine and merocyanine dyes due to its ability to improve photostability and shift absorption/emission to longer wavelengths. Also utilized in materials for nonlinear optics and in some pharmaceutical intermediates where a planar, electron-rich scaffold is beneficial.