 A phosphorodiamidate (or diamidophosphate) is a phosphate that has two of its OH groups substituted by NR2 groups to give a species with the general formula O=P(OH)(NH2)2.The substitution of all three OH groups gives the phosphoric triamides (O=P(NR2)3), which are commonly referred to as phosphoramides.Two examples of natural phosphoramidates are phosphocreatine and the phosphoramidate formed when histidine residues in histidine kinases are phosphorylated.