Although distinguished when they act as ligands for transition metals, the names amides and imidic acids are synonyms describing two different anions.
However, they are distinguished when they act as ligands for transition metals, with O-bound species referred to as imidates and N-bound species referred to as amidates. Since amides and imidic acids are tautomers, they form the same anion upon deprotonation. An amidate/imidate anion is formed upon deprotonation of an amide or imidic acid. 
