文摘
Global and local descriptors of chemical reactivity and selectivity are used in order to characterize the natureof the active species of bis(imino)pyridyl iron, a catalyst for olefin polymerization. It is shown that chemicalpotential, hardness, electrophilicity, as well as the dual and multiphilic descriptors for chemical reactivityand selectivity, are adequate for characterizing the global and local reactivity trends of this organo-metalliccomplex. Most theoretical evidence presented in this paper indicates that the catalyst of Fe+3 seems to bemore active for olefin polymerization than that of Fe+2. However, when the cocatalyst is considered, catalystsof Fe+2 and Fe+3 present similar electrophilic activity to orientate the nucleophilic attack. It is observed thatthis activity is well localized at the metallic center in the ferric species whereas it appears to be more delocalizedon the ligands of the ferrous species.