Ammonium Salts of Phosphoglycolic Acid (H₃PG): NH₄. H₂PG, 3NH₄. H₂PG. HPG, 2NH₄. HPG and 3NH₄.PG.H₂O at 150K

The structures have been determined of four ammonium phosphoglycolate (PG) salts: ammonium phosphoglycolate(1-), NH₄.H₂PG (I), triammonium phosphoglycolate(1-) phosphoglycolate(2-), 3NH₄.H₂PG.HPG (II), diammonium phosphoglycolate(2-), 2NH₄.HPG (III) and triammonium phosphoglycolate(3-) monohydrate, 3NH₄.PG.H₂O (IV) (PG = C₂H₂O₆P^3-). The P-O(ester) bond in the doubly ionized phosphate group of IV [1.625 (2) Å] is longer than those in mono-ionized phosphate groups [1.580 (2)-1.600 (1) Å]. There are extensive networks of hydrogen bonds in all four crystals in which every O- and N^--bonded H atom is involved.

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