Switchable Synthesis
of Ethylene/Acrylate Copolymers
by a Dinickel Catalyst: Evidence for Chain Growth on Both Nickel Centers
and Concepts of Cation Exchange Polymerization
posted on 2024-03-25, 10:43authored byShuoyan Xiong, Heather A. Spinney, Brad C. Bailey, Briana S. Henderson, Adjeoda A. Tekpor, Matthew R. Espinosa, Paramita Saha, Theodor Agapie
A dinickel complex, X-Ni2,
was developed and demonstrated to have a high performance in ethylene/acrylate
copolymerization. Further mechanistic studies revealed that X-Ni2 performs acrylate insertion
at both Ni centers at distinct rates. Addition of NaBArF24 to X-Ni2 leads
to 1:1 binding and serves as a switch for tuning catalytic activity,
copolymer MW and acrylate incorporation. NMR studies of cation binding,
when present in substoichiometric amounts, suggest a dynamic process
involving cation exchange. This phenomenon provides an alternative
strategy for controlling chain growth in polar polyolefin synthesis
and was probed herein.