Phosphorus forms two types of halides, PX3 (X = F, Cl, Br, I) and PX5 (X = F, Cl, Br).
- Passing dry chlorine over heated white phosphorus, Phosphorus Trichloride is prepared :
- Action of thionyl chloride with white phosphorus.
- It is a colourless oily liquid
- It hydrolyses in the presence of moisture
- It reacts with organic compounds containing –OH group
- It has a pyramidal shape, in which phosphorus is sp3 hybridised.
It is prepared by the reaction of white phosphorus with excess of dry chlorine
Action of SO2Cl2 on phosphorus
- It is a yellowish white powder
- In moist air, it hydrolyses to POCl3 and finally gets converted to phosphoric acid
- When heated, it sublimes but decomposes on stronger heating
- It reacts with organic compounds containing –OH group converting them to chloro derivatives
- Finely divided metals on heating with PCl5 give corresponding chlorides
- It is used in the synthesis of some organic compounds
- In gaseous and liquid phases, it has a trigonal bipyramidal structure
- In the solid state it exists as an ionic solid, [PCl4]+[PCl6]– in which the cation, [PCl4]+ is tetrahedral and the anion, [PCl6]–octahedral.