Regiochemistry of propene insertion with group 4 polymerization catalysts from a theoretical perspective

The regiochemistry of monomer insertion in propene polymerization promoted by group 4 metal catalysts has been investigated by using DFT methods. We calculated primary and secondary propene insertion on metallocenes, constrained geometry catalysts and post-metallocene systems analyzing the effects of ligand framework, growing chain and metal. Our study supports the concept that for metallocene-based catalysts the regiochemistry of propene is mainly originated by steric effects. Instead, for octahedral systems a delicate balance between steric and electronic effects is found. This allows to play with the electronic properties of the ligand framework to tune finely the regiochemistry of polymerization.