Compounds of Phosphorus - Phosphine



Methods of preparation of phosphine

1. From metal phosphides:
2. From phosphorous acid:
3. From phosphonium iodide:


Structure of phosphine

It is hybridised. Three of the four orbitals with 1s-orbitals of hydrogen atoms to form three -bonds while the fourth one contains the lone pair of electrons.


Physical properties of phosphine

  • It is a colourless gas having rotten fish smell.
  • It is highly poisonous gas.


Chemical properties of phosphine

  • is sparingly soluble in water and soluble in organic solvents.
  • acts as a Lewis base by donating its lone pair of electrons when it reacts with hydrogen iodide.
  • Under normal conditions it is a non-combustible gas,but when heated it catches fire which results in the formation of phosphoric acid.


  • When it comes in contact with oxidizing agents it explodes violently.


Uses of phosphine

  • In semiconductor industries it is used in small amounts as a dopant
  • is used in Holmes signal due to its property of spontaneous combustion
  • For the production of smoke screens