Theoretical study of cation–π interactions of the metal complex cation, [Co(NH3)6]3+, with ethylene and acetylene Original Research Article

Cation–π interactions between a transition metal complex cation and ethylene and acetylene are predicted. The presented calculations on the [Co(NH3)6]3+–C2H4 and [Co(NH3)6]3+–C2H2 systems demonstrate that a transition metal complex cation can interact strongly with the double and triple bonds. The bonding energies obtained with the B3LYP method are 17.02 kcal/mol for ethylene π complex and 18.30 kcal/mol for acetylene π complex. In the most stable structure of the ethylene π complex, three NH3 groups interact with the π system of ethylene, whereas in the most stable structure of the acetylene π complex, two NH3 groups interact with the π system of acetylene.