Iron Complex Catalyst for Olefin Oligomerization Efficiency

The patent employs a composite catalyst system combining iron complex with specific ligands (Formula 1) and trialkylaluminum co-catalyst. This composite approach creates synergistic effects where the iron center provides catalytic activity while the ligand framework stabilizes the active species, achieving both high productivity and reliable polymerization activity maintenance throughout the reaction process.

The patent optimizes specific parameters including the ligand structure (R groups with 1-6 carbon atoms or aromatic groups with 6-12 carbon atoms), the halogen type (Cl or Br), and the trialkylaluminum selection (particularly trimethylaluminum). These parameter optimizations enable the catalyst to achieve peak efficiency while maintaining stable activity, resolving the contradiction between productivity and reliability.

The patent introduces ligands with specific local structural characteristics (R groups containing 1-6 carbon atoms or aromatic groups with 6-12 carbon atoms) that create localized electronic and steric environments around the iron center. This local quality control enables precise modulation of the catalyst's interaction with monomers, achieving both excellent molecular weight distribution control and high catalyst efficiency simultaneously.

The trialkylaluminum compound serves as an intermediary that activates the iron complex catalyst and mediates the oligomerization process. This intermediary enables precise control over the catalytic cycle, allowing the system to achieve high productivity while maintaining narrow molecular weight distributions through controlled monomer insertion and chain transfer processes.