Direct synthesis of polyethylene containing two kinds of heteroatoms by scandium complexes

Abstract

Polar polyolefins are of fundamental interest and practical significance. The direct synthesis of polyethylene containing two kinds of heteroatoms by early transition catalysts is still rare due to the complicated poisoning action, but these novel copolymers may exhibit superposed and unexpected characteristics. Herein we report the production of polyethylene containing two distinct polar groups (such as O, S and F) by scandium complexes. Sc-2 with a bulkier ligand can raise polar olefin incorporation. S and F atoms on comonomer 1g (2S/F-o) show significantly positive effects during copolymerization with ethylene, resulting in a high incorporation ratio (17.2 to 44.9 mol%), high activity (69.0 to 211 kg mol_Sc⁻¹ h⁻¹ bar⁻¹) and high molecular weight (M_n) up to 33.3 × 10⁴ g mol⁻¹. The polymerization mechanistic aspect of cooperative action between S and F atoms on 1g was elucidated through DFT studies. We expect that our new findings could guide the synthesis of polyolefins containing multi-functional groups.