Cation–π interaction with transition-metal complex as cation

A novel type of cation–π interaction, where a transition-metal complex cation interacts with a π-system, is predicted here. The theoretical calculations on the [Co(NH3)6]3+–C6H6 system presented demonstrate that a transition-metal complex cation can interact strongly with π-systems. The bonding energy obtained with the B3LYP method is 31.34 kcal/mol. In the most stable structure, three NH3 groups from [Co(NH3)6]3+ interact with the π-system of benzene.