Simple Preparation of Halogen-Substituted <i>α</i>-Diimine Nickel Complexes Immobilized into Clay Interlayer as Catalysts for Ethylene Oligo-/Polymerization

Abstract

In the practical use for the production of the α-olefins, it is highly desired to develop a novel heterogeneous catalyst system. The metal complexes immobilized into the clay interlayers show a great potential as heterogeneous catalysts due to their excellent processability. In this study, nine types of heterogeneous procatalyst Ln/Ni 2+ -micas were synthesized via a one-pot preparation method, . A high catalyst activity was obtained when the substituent having a larger steric bulk than that of a methyl substituent was introduced at the ortho-position of the aryl rings. The introduction of the fluorine substituent as a strong electron-withdrawing group to the para-position also increased the catalytic activity. The L2, L4, L5, and L6/Ni 2+ -micas showed moderate selectivities to oligomers consisting of C 4 -C 20 in the range of 19.9 -41.6 wt% at 50˚C. The calculated Schulz-Flory constants α based on the mole fraction of C 12 and C 14 were within 0.61 -0.78.

Evaluation of Bis(imino)pyridine Iron Catalyst on Heterogeneous Ethylene Polymerization

“…These metallic sites present a tendency to broad polydispersity (M w /M n ), due to the electronic nature of the metal. In turn, the catalysts studied in this work do not present this architecture, resulting in the production of oligomers with different chain sizes, in agreement with the literature [23].…”