The pentaamminecobalt(III) complex of 1,2-dicyanobenzene reacts with a stoichiometric amount of base to give the coordinated carboxamido complex (NH3)5Co(2-carboxamidobenzonitrile)2+. The latter complex cyclizes in base to the pentaamminecobalt(III) complex of 1-oxo-3-iminoisoindolin-2-yl. However, in acid solution the coordinated amide complex undergoes an intramolecular rearrangement to form the coordinated nitrile-free amide compound (NH3)5Co(2-cyanobenzamide)3+. This nitrile complex is rapidly hydrolyzed, the reaction involving intramolecular catalysis by the free amide group. The product of the hydrolysis reaction, (NH3)5Co(2-carboxamidobenzamide)2+, cyclizes in acidic solution to (NH3)5Co(1-oxo-3-iminoisoindoline)3+ where the metal is coordinated to the exocyclic nitrogen (3 position). The characterization of the above complexes is described, and mechanisms for their formation are considered.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry