Facing Unexpected Reactivity Paths with ZrIV-Amidopyridinate Polymerization Catalyst

This work provides original insights to the better understanding of the complex structure–activity relationship of ZrIV–pyridylamido-based olefin polymerization catalysts and highlights the importance of the metal-precursor choice (ZrACHTUNGTRENUNG(NMe2)4 vs. Zr(Bn)4) to prepare precatalysts of unambiguous identity. A temperature-controlled and reversible s-bond metathesis/protonolysis reaction is found to take place on the ZrIV-amido complexes in the 298–383 K temperature range, changing the metal coordination sphere dramatically (from a five-coordinated tris-amido species stabilized by bidentate monoanionic {N,N} ligands to a six-coordinated bisamido–mono-amino complexes featured by tridentate dianionic {N,N,C} ligands).