Showing papers by "Richard F. Jordan published in 2020"
TL;DR: In this paper, the synthesis and ethylene reactivity of a new family of dinuclear Co2Br4 and Fe2br4 complexes supported by binucleating macrocyclic bis(pyridine-diimine) (PDI) ligands that contain 4,4″-R2-3,3″-o.
9 citations
TL;DR: The molecular weight distributions of the copolymers produced by D and E are generally narrower than for catalyst C, which suggests that the Zn-phosphonate cores of D andE are more stable than the Li-sulfonate-chloride core of C under copolymerization conditions.
Abstract: The self-assembled multinuclear PdII complexes {(Li-OPOOMe2)PdMe(4-5-nonyl-pyridine)}4Li2Cl2 (C, Li-OPOOMe2 = PPh(2-SO3Li-4,5-(OMe)2-Ph)(2-SO3--4,5-(OMe)2-Me-Ph)), {(Zn-OP-P-SO)PdMe(L)}4 (D, L = pyridine or 4-tBu-pyridine, [OP-P-SO]3- = P(4-tBu-Ph)(2-PO32--5-Me-Ph)(2-SO3--5-Me-Ph)), and {(Zn-OP-P-SO)PdMe(pyridine)}3 (E) copolymerize ethylene and vinyl fluoride (VF) to linear copolymers. VF is incorporated at levels of 0.1-2.5 mol% primarily as in-chain -CH2CHFCH2- units. The molecular weight distributions of the copolymers produced by D and E are generally narrower than for catalyst C, which suggests that the Zn-phosphonate cores of D and E are more stable than the Li-sulfonate-chloride core of C under copolymerization conditions. The ethylene/VF copolymerization activities of C-E are over 100 times lower and the copolymer molecular weights (MWs) are reduced compared to the results for ethylene homopolymerization by these catalysts.