α,α′-Bis(arylimino)-2,3:5,6-bis(pentamethylene)pyridylcobalt Chlorides: Synthesis, Characterization, and Ethylene Polymerization Behavior

Abstract

A series of α,α′-bis(arylimino)-2,3:5,6-bis(pentamethylene)pyridylcobalt chlorides was synthesized by the one-pot template reaction of α,α′-dioxo-2,3:5,6-bis(pentamethylene)pyridine, anilines, and cobalt chloride in refluxing acetic acid. The molecular structure of complex Co1 was determined by single-crystal X-ray crystallography, which revealed a distorted square-pyramidal geometry around the cobalt center. On activation with methylaluminoxane or modified methylaluminoxane, all of the complexes exhibited high activity toward ethylene polymerization with activities in the range of 10⁶ g of polyethylene (PE) per mole of Co per hour and produced highly linear PEs with low molecular weights and narrow polydispersity. The unimodal nature of the PEs indicated single-site active species of these cobalt catalyst systems. The influences of cobalt complexes and polymerization parameters on the catalytic behavior and the properties of the PEs were investigated in detail.

α,α′-Bis(arylimino)-2,3:5,6-bis(pentamethylene)pyridylcobalt chlorides showed high activity toward ethylene polymerization and produced highly linear polyethylenes with low molecular weights and narrow polydispersity owing to the single-site active species of these cobalt catalyst systems.

from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/1UGbMMz
via IFTTT