Definition of amidium ions

1. Cations formally derived by the addition of one hydron to the N or O atom of an amide and N-hydrocarbyl derivatives thereof. In organic chemistry an unspecified amidium ion is commonly a carboxamidium ion: RC(OH)=N+R2 RC(=O+H)NR2 or RC(=O)N+R3. The term does not imply knowledge concerning the position of the cationic centre. RNRI Rule RC-82.1.2. E.g. PhC(=O)N+Me 3 N,N,N-trimethylbenzamid