“…Therefore, both factors must be balanced when predicting the effect of an electron donor substituent on the catalyst activity. In the present case, some theoretical studies (PM3 and DFT) have been performed and preliminary results show that, in fact, the stability of the p-complex is lower than that of the [NiBr 2 (MesBIAN)] [29]. Studies on the activation energies of the insertion reactions are underway.…”