Nitrilotrimetaphosphoric acid

Nitrilotrimetaphosphoric acid is said to be formed by heating crude imidodiphosphoric acid to 290°-300° C., washing out ammonium chloride, dissolving the residue in ammonia, acidifying and filtering off the white precipitate. The solution contained this acid,



which yielded a crystalline sodium salt.

These compounds are made by the application of a few general methods:—

1. By the action of ammonia on thiophosphoryl halides.
2. By the action of ammonia on sulphides of phosphorus.
3. By heating ammonium chloride with sulphides of phosphorus.