The Role of Bulky Substituents in Brookhart-Type Ni(Ⅱ) Diimine Catalyzed Olefin Polymerization: A Combined Density Functional Theory and Molecular Mechanics Study

摘要

The role of the bulky ligands in Ni(Ⅱ)diimine catalyzed ethylene polymerization has been examined with a combined density functional theory quantum mechanics and molecular mechanics (QM/MM) model. Specifically, we have examined the catalytic center or the type (ArN=C(R)-C(R)=NAr)Ni~Ⅱ-R'~+, where R=Me and Ar= 2, 6-C_6H_3(I-Pr)_2. The Ar and R groups were treated by a molecular mechanics force field while density functional theory was applied to the remainder of the system.