Density functional theory study of two state reactivity of NO activation on iron dimer

The mechanism of Fe₂+NO (octet and decuplet) was calculated by the density functional theory (DFT) with the B3LYP methods combined with the 6-311+G (d, p) basis set. The geometry optimizations of reactants, transition states, intermediates and products of the reactions of triplet and quartet states were completely made, and all the transition states were verified by the vibration analysis and the intrinsic reaction coordinate calculations. The 'Two State Reactivity (TSR)' was used to analyze the reaction mechanism. The result showed that the two crossing points can effectively lower the activation energy of reaction, which plays a beneficial role in the kinetic and thermodynamic aspects of this reaction. And the breaking of Fe-N bond is the rate-determining step. (authors)