Diphenylphosphinic acid is widely used as a key intermediate in the synthesis of various organophosphorus compounds. It plays a significant role in the production of flame retardants, which are incorporated into polymers and plastics to enhance their fire resistance. Additionally, it serves as a ligand in coordination chemistry, facilitating the formation of metal complexes used in catalysis and material science. The compound is also employed in the development of pharmaceuticals, particularly in the creation of drugs targeting neurological disorders. Its application extends to the field of organic synthesis, where it acts as a reagent for constructing complex molecular structures. Furthermore, diphenylphosphinic acid is utilized in the preparation of corrosion inhibitors, which protect metal surfaces in industrial settings.