Reversible trans-alkylation mechanisms at homogeneous catalytic systems investigated by a combined DFT and ASM-NEDA approach

Abstract

We studied the reversible trans-alkylation(s) mechanism for the chain shuttling process by means of density functional theory (DFT) calculations combined with%VBur steric maps and the Activation Strain Model (ASM) coupled with Natural Energy Decomposition Analysis (NEDA). Our results revealed that the two partners of the catalytic pair involved in the industrial process for olefin-based block copolymers formation show comparable coordination energies with the chain shuttling agent and this similarity is due to the (fortuitus) ligand modification in situ by one of the two systems. The further extension of our analysis to several ligand classes (from ansa-metallocenes to octahedral nonmetallocenes) rule out the possibility of using binary catalysts with different coordination geometries as suitable pair.