Ammonium dihydrogen phosphate Ammonium dihydrogen phosphate Ammonium dihydrogen phosphate (ADP), commonly called monoammonium phosphate (MAP) is a chemical compound with formula . It is a white crystalline solid consisting of ammonium cations and dihydrogen phosphate anions in equal proportions. ADP is a major ingredient of agricultural fertilizers and some fire extinguishers. It also has significant uses in optics and electronics. Monoammonium phosphate is soluble in water and crystallizes from it as the anhydrous salt in the tetragonal system, as elongated prisms or needles. It is practically insoluble in ethanol. Solid monoammonium phosphate can be considered stable in practice for temperatures up to 200
Dihydrogen complex separations > 1 Å are better described as dihydride complexes (see figure). The usual method for characterization is H NMR spectroscopy. The magnitude of spin-spin coupling, "J", is a useful indicator of the strength of the bond between the hydrogen and deuterium in HD complexes. For example, "J" is 43.2 Hz in HD but 33.5 Hz in W(HD)(CO)(PPr). Dihydrogen complexes typically have shorter H-spin-lattice relaxation times than the corresponding dihydrides. An ideal if nontrivial method of characterization of dihydrogen complexes is neutron diffraction. Neutrons interact strongly with hydrogen atoms, which allows one to infer their location in a crystal. In