Copolymerization of Ethylene and Vinyl Fluoride by Self-Assembled Multinuclear Palladium Catalysts

摘要

The self-assembled multinuclear Pd complexes {(Li-OPO )PdMe(4-5-nonyl-pyridine)} Li Cl ( , Li-OPO = PPh(2-SO Li-4,5-(OMe) -Ph)(2-SO -4,5-(OMe) -Me-Ph)), {(Zn-OP-P-SO)PdMe(L)} ( , L = pyridine or 4- Bu-pyridine, [OP-P-SO] = P(4- Bu-Ph)(2-PO -5-Me-Ph)(2-SO -5-Me-Ph)), and {(Zn-OP-P-SO)PdMe(pyridine)} ( ) copolymerize ethylene and vinyl fluoride (VF) to linear copolymers. VF is incorporated at levels of 0.1–2.5 mol% primarily as in-chain -CH CHFCH - units. The molecular weight distributions of the copolymers produced by and are generally narrower than for catalyst , which suggests that the Zn-phosphonate cores of and are more stable than the Li-sulfonate-chloride core of under copolymerization conditions. The ethylene/VF copolymerization activities of – are over 100 times lower and the copolymer molecular weights (MWs) are reduced compared to the results for ethylene homopolymerization by these catalysts.