Acrylonitrile polymerization by Cy3PCuMe and (Bipy)2FeEt2

Area of Science:

• Organometallic Chemistry
• Polymer Chemistry

Background:

• Organocopper complexes are known catalysts for various chemical transformations.
• Ligand redistribution and ion pair formation can significantly influence reactivity.

Purpose of the Study:

• To investigate the low-temperature behavior of Cy(3)PCuMe.
• To elucidate the mechanism of acrylonitrile polymerization initiated by organocopper complexes.

Main Methods:

• Nuclear Magnetic Resonance (NMR) spectroscopy to characterize the ion pair.
• Stoichiometric analysis of the equilibrium.
• Reverse synthesis to confirm the ion pair structure.
• Polymerization experiments to study initiation mechanisms.

Main Results:

• Cy(3)PCuMe redistributes to form the ion pair [Cu(PCy(3))(2)][CuMe(2)] at low temperatures.
• The ion pair structure was confirmed by NMR and synthesis.
• Complex 1, free PCy(3), and an iron complex initiate acrylonitrile polymerization.
• Polymerization proceeds via an anionic mechanism, with PCy(3) being the primary initiator from complex 1.

Conclusions:

• Low-temperature ligand redistribution in Cy(3)PCuMe leads to ion pair formation.
• Tricyclohexylphosphine (PCy(3)) is a key initiator for acrylonitrile polymerization, either free or liberated from the copper complex.
• Anionic polymerization mechanism is confirmed for these initiation systems.