A Heterogeneous Palladium Catalyst for the Polymerization of Olefins Prepared by Halide Abstraction Using Surface R3Si+ Species. Issue 20 (16th March 2022)

• Record Type: Journal Article
• Authors: Gao, Jiaxin; Dorn, Rick W.; Laurent, Guillaume P.; Perras, Frédéric A.; Rossini, Aaron J.; Conley, Matthew P.
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 20(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-16
• Subjects: Heterogeneous Catalysis -- Olefin Polymerization -- Palladium -- Polar Monomer -- Solid-State NMR; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202117279
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The silylium‐like surface species [ i Pr3 Si][(R F O)3 Al−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 ][(R F O)3 Al−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 Na[B(Ar F )4 ]. Multinuclear 13 C{ 27 Al} RESPDOR and 1 H{ 19 F} S‐REDOR experiments are consistent with a weakly coordinated ion‐pair between (N^N)Pd−CH3 + and [(R F O)3 Al−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. Abstract : A silylium‐like ion supported on silica ionizes a Pd−Cl complex by chloride abstraction to generate a very active catalyst for (co‐)polymerization reactions.