Antimonyl Dihydrogen Phosphite, (Sb0)H₂PO₃

Antimonyl Dihydrogen Phosphite, (Sb0)H₂PO₃, has been obtained by the action of phosphorous acid upon antimony trioxide, and also by the action of potassium antimonyl tartrate upon an ammoniacal solution of phosphorus trichloride. It is a white powder, which, in solution in dilute hydrochloric acid, is capable of acting as a reducing agent.