A Heterogeneous Palladium Catalyst for the Polymerization of Olefins Prepared by Halide Abstraction Using Surface R3Si+ Species

摘要

Abstract The silylium‐like surface species iPr3Si(RFO)3Al?OSi≡) activates (N^N)Pd(CH3)Cl (N^N=Ar?N=CMeMeC=N?Ar, Ar=2,6‐bis(diphenylmethyl)‐4‐methylbenzene) by chloride ion abstraction to form (N^N)Pd?CH3(RFO)3Al?OSi≡) (1). A combination of FTIR, solid‐state NMR spectroscopy, and reactions with CO or vinyl chloride establish that 1 shows similar reactivity patterns as (N^N)Pd(CH3)Cl activated with NaB(ArF)4. Multinuclear 13C{27Al} RESPDOR and 1H{19F} S‐REDOR experiments are consistent with a weakly coordinated ion‐pair between (N^N)Pd?CH3+ and (RFO)3Al?OSi≡). 1 catalyzes the polymerization of ethylene with similar activities as (N^N)Pd?CH3+ in solution and incorporates up to 0.4? methyl acrylate in copolymerization reactions. 1 produces polymers with significantly higher molecular weight than the solution catalyst, and generates the highest molecular weight polymers currently reported in copolymerization reactions of ethylene and methylacrylate.