Theoretical Study on the Reaction Complexing Olefins with Nickel Dithiolene

Economic and powerful olefins separation is the most important technology for the energy optimisation and reduction of fossil fuel in petrochemical industry. On account of that the specific structures of olefins will make some influences on the separation, in this work, by means of density functional theory, we perform a theoretical estimation of the olefin-structure-induced effects on the reaction of nickel dithiolene with olefins. It is shown that the reaction complexing olefins with Ni dithioloene is a two-step process with the first step being the rate-determining one. As the number of carbon atoms in the olefins increases, the activation energy of any step will increase, while the reaction rate and the equilibrium constant will decrease. Furthermore, it demonstrates that the increase of the carbon atom number in olefins will suppress the reaction, and decrease the production rate, which provides a way of separating the olefins with different numbers of carbon atoms. Then we consider the influences on the reaction induced by the transor cis-structure in olefins. It is verified that the reaction between nickel dithiolene and trans-structure olefin will be much easier and faster to occur, but the product has a smaller stability than that of cis-structure olefin. This work should be of some significance for estimating the reaction rate and product rate in olefin separation.