A DFT Study of the Copolymerization of Methyl Vinyl Sulfone and Ethylene Catalyzed by Phosphine–Sulfonate and α-Diimine Palladium Complexes

Density functional theory (DFT) calculations were comparatively carried out to reveal the origins of different catalytic performances from phosphine–benzene sulfonate (A, [{P^O}PdMe(L)] (P^O = Κ2-P,O-Ar2PC6H4SO3 with Ar 2-MeOC6H4)) and α-diimine (B, [{N^N}PdMe(Cl)] (N^N (ArN=C(Me)-C(Me)=NAr) 2,6-iPr2C6H3)) palladium complexes toward copolymerization ethylene methyl vinyl sulfone (MVS). Having achieved agreement between experiment, it was found that favorable 2,1-selective insertion MVS into phosphine–sulfonate complex A due there being less structural deformations in catalyst monomer. Both insertions calculated, former be more for chain initiation propagation. In case system B, resulting product first quite stable, stronger O-backbiting interaction hampered incoming molecule. These computational results are expected provide some hints design transition metal catalysts.