Phosphoramidates (sometimes also called amidophosphates) are a class of phosphorus compounds structurally related to phosphates (or organophosphates) via the substitution of an OR for a NR2. The structure of phosphoramidic acid (phosphoramidate), (HO)2PONH2, is present in PubChem.
A phosphorodiamidate is a phosphate that has two of its OH groups substituted by NR2 groups to give a species with the general formula HOPO(NH)2.
Two examples of natural phosphoramidates are phosphocreatine and the phosphoramidate formed when histidine residues in histidine kinases are phosphorylated. An example of a phosphorodiamidate is Morpholino which is used in molecular biology.