Structure−Activity Correlation in Titanium Single-Site Olefin Polymerization Catalysts Containing Mixed Cyclopentadienyl/Aryloxide Ligation

Abstract

In this work, we report the synthesis of eighteen titanium cyclopentadienyl aryloxide complexes and their propagation rate constants for 1-hexene polymerization. A correlation between kp values and the underlying catalyst structures is developed using DFT-computed ligand cone angles and ion pair separation energies as structural and electronic descriptors. The correlation takes the form of an Arrhenius-like relationship where the pre-exponential factor is correlated to the ligand cone angles and the activation energy term is correlated to the ion pair separation energies. This finding is consistent with the idea that the ability of the monomer to access the metal center is a key factor affecting the reaction rate.