Di(naphthalen-2-yl)phosphine oxide is primarily used in organic synthesis and material science. It serves as a key intermediate in the preparation of phosphorescent materials, which are essential for organic light-emitting diodes (OLEDs) and other optoelectronic devices. Its structure allows for efficient electron transport and charge balance in these applications. Additionally, it is utilized in the development of ligands for catalysis, particularly in transition metal-catalyzed reactions, due to its ability to stabilize metal centers and enhance reaction efficiency. Its thermal stability and electronic properties also make it suitable for use in advanced polymer materials, where it can improve durability and performance.