A theoretical study on the mechanism of the reaction between Cl atoms and nitrobenzene

The potential energy surface for the C6H5NO2 + Cl reaction was explored at the DFT (B3LYP) and MP2 levels of theory, using different basis sets. The large spin contaminations inherent to the MP2 calculations suggest that the DFT results should be preferred. Further coupled-cluster calculations should help to confirm that preference. Energies were estimated at the QCISD(T)//B3LYP level. The DFT(B3LYP) energy profile is consistent with the experimental observation that the rate constant does not exhibit any pressure dependence. The reaction proceeds via a displacement mechanism.