Phosphorous trichloride

Phosphorus trichloride is a chemical compound of phosphorus and chlorine, having the chemical formula PCl3. It has a trigonal pyramidal shape. It is the most important of the three phosphorus chlorides. It is an important industrial chemical, being used for the manufacture of organophosphorus compounds for a wide variety of applications. It has a 31P NMR signal at around +220 ppm with reference to a phosphoric acid standard. Phosphorus trichloride is a chemical compound of phosphorus and chlorine, having the chemical formula PCl3. It has a trigonal pyramidal shape. It is the most important of the three phosphorus chlorides. It is an important industrial chemical, being used for the manufacture of organophosphorus compounds for a wide variety of applications. It has a 31P NMR signal at around +220 ppm with reference to a phosphoric acid standard. The phosphorus in PCl3 is often considered to have the +3 oxidation state and the chlorine atoms are considered to be in the −1 oxidation state. Most of its reactivity is consistent with this description. PCl3 is a precursor to other phosphorus compounds, undergoing oxidation to phosphorus pentachloride (PCl5), thiophosphoryl chloride (PSCl3), or phosphorus oxychloride (POCl3). If an electric discharge is passed through a mixture of PCl3 vapour and hydrogen gas, a rare chloride of phosphorus is formed, diphosphorus tetrachloride (P2Cl4). Phosphorus trichloride is the precursor to organophosphorus compounds that contain one or more P(III) atoms, most notably phosphites and phosphonates. These compounds do not usually contain the chlorine atoms found in PCl3. PCl3 reacts vigorously with water to form phosphorous acid, H3PO3 and HCl: A large number of similar substitution reactions are known, the most important of which is the formation of phosphites by reaction with alcohols or phenols. For example, with phenol, triphenyl phosphite is formed: where 'Ph' stands for phenyl group, -C6H5. Alcohols such as ethanol react similarly in the presence of a base such as a tertiary amine: In the absence of base, however, the reaction proceeds with the following stoichiometry to give diethylphosphite: