Phosphine

Structural formula of phosphine

Phosphine is a chemical compound with the formula PH_. It is a colorless, flammable, and toxic gas with a distinctively unpleasant odor, similar to that of garlic or rotting fish. Phosphine is a pnictogen hydride and is classified as a hydride of phosphorus.

Properties

Phosphine is a polar molecule with a trigonal pyramidal molecular geometry. The phosphorus atom in phosphine is bonded to three hydrogen atoms, and it has a lone pair of electrons, which contributes to its shape and polarity. The bond angles in phosphine are approximately 93.5 degrees, which is smaller than the typical tetrahedral angle of 109.5 degrees due to the repulsion of the lone pair.

Production

Phosphine can be produced by several methods, including the reaction of white phosphorus with sodium hydroxide or by the hydrolysis of calcium phosphide. Industrially, it is often produced by the reaction of phosphorus trichloride with water or alcohols.

Uses

Phosphine is used in various industrial applications, including as a fumigant for stored grain and as a precursor to other phosphorus compounds. It is also used in the semiconductor industry for the doping of silicon and other materials.

Safety

Phosphine is highly toxic and poses significant health risks if inhaled. It can cause symptoms such as nausea, dizziness, and respiratory distress. In high concentrations, it can be fatal. Proper safety precautions, including the use of gas detectors and ventilation systems, are essential when handling phosphine.

Related pages

• Phosphorus
• Hydride
• Pnictogen
• Toxic gas