A Bulky Pd(II) α-Diimine Catalyst Supported on Sulfated Zirconia for the Polymerization of Ethylene and Copolymerization of Ethylene and Methyl Acrylate

The reaction of (N boolean AND N)PdMe2 (N boolean AND N is Ar-N=CMe-MeC=N-Ar; Ar = 2,6-bis(diphenylmethyl)-4-methylbenzene) and sulfated zirconia (SZO) in diethyl ether forms organometallic Pd-sites that polymerize ethylene and copolymerize ethylene and methyl acrylate. The Pd-sites bind CO and were studied by infrared and solid-state NMR spectroscopies. Analysis of the reaction mixture shows that more methane than expected evolves during the grafting reaction, suggesting that some Pd-sites do not contain a Pd-Me group. Consistent with this observation, deuterium labeling experiments show that 9% of palladium sites are active in polymerization reactions. (N boolean AND N)PdMe2/SZO polymerizes ethylene with activity as high as 1342 kg(PE)/(mol(active) (Pd)*h) and incorporated up to 0.46% methyl acrylate in copolymerization reactions.