Enhancing the Activity and Thermal Stability of Iron Precatalysts Using 2‐(1‐{2,6‐bis[bis(4‐fluorophenyl)methyl]‐4‐methylphenylimino}ethyl)‐6‐[1‐(arylimino)ethyl]pyridines

Abstract

Abstract A series of 2‐(1‐{2,6‐bis[bis(4‐fluorophenyl)methyl]‐4‐methylphenylimino}ethyl)‐6‐ [1‐(arylimino)ethyl]pyridine ligands is synthesized and fully characterized. The corresponding iron complexes are prepared and characterized by single‐crystal X‐ray diffraction for representative iron complexes, among other methods, revealing a pseudo square‐pyramidal geometry at the iron center. Upon activation with MMAO, all iron precatalysts exhibit high activity in ethylene polymerization, producing linear polyethylene. The observed activity is the highest reported for iron‐based precatalysts of this type. The polymerization parameters are shown to strongly affect the catalytic behavior, and both the activity and the polymer properties (i.e. $ \overline{M}_{\rm w}$ or $ \overline{M}_{\rm w}$ / $ \overline{M}_{\rm n}$ ) can be controlled.