Preparation, properties and uses of phosphine

Preparation

(i) From Phosphide

By the reaction of phosphides with water.

Aluminium phosphide is decomposed with dilute sulphuric acid.

(ii) From Phosphorus acid

Phosphorus acid decomposes when heated to give a pure sample of phosphine.

Structure

Phosphine has the following electronic structure.

Structure of phosphine

The electronic structure of phosphine is similar to ammonia in that it has a pyramidal structure. The bond angle H-P-H, however, is = 93^o (e.g., NH₃ =107^o)