Chain-Straightening Polymerization of Olefins to Form Polar Functionalized Semicrystalline Polyethylene

• Published in: Organometallics 2022-11, Vol.41 (22), p.3411-3418
• Main Authors: Eagan, James M., Padilla-Vélez, Omar, O’Connor, Kyle S., MacMillan, Samantha N., LaPointe, Anne M., Coates, Geoffrey W.
• Format: Article
• Language: English
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/acs.organomet.2c00366

We report the design and synthesis of an α-diimine PdII catalyst that copolymerizes functionalized and long chain α-olefins to produce semicrystalline polyethylene materials. Through a chain-straightening polymerization mechanism, the catalyst afforded high-melting point polymers with T m values of up to 120 °C. The chain-straightening polymerization operates with high [ω,1]-insertion selectivity at high alkene concentrations and with varying α-olefin chain lengths, including propylene. The Pd catalyst can copolymerize 1-decene and methyl decenoate into semicrystalline ester-functionalized polymers with incorporation percentages proportional to the comonomer ratio (up to 13 mol %). 13C nuclear magnetic resonance and isotope labeling studies revealed that the improved selectivity relative to those of other systems arises from a high selectivity for [2,1]-insertion (96%) coupled with rapid chain-walking for a total of 90 mol % of 1-decene undergoing net [10,1]-insertion.