Used as a key reagent in organic synthesis, particularly in the Arbuzov and Michaelis–Arbuzov reactions to prepare phosphonates, which are important in the production of pharmaceuticals, agrochemicals, and flame retardants. Acts as a reducing agent and a ligand in coordination chemistry. Employed in the synthesis of pesticides and plasticizers due to its ability to introduce phosphorus-containing groups into organic molecules. Also utilized in the preparation of specialty chemicals for the electronics industry, including semiconductors and photoresists.