The nature of nickel(II) species, formed upon the activation of α-diiminonickel pre-catalyst LNNiIIBr2 (LN = 1,2-Bis[(2,4,6-trimethylphenyl)imino]acenaphthene) with Al2Et3Cl3 and Al2Me3Cl3, has been studied using 1H and 2H NMR spectroscopy. The paramagnetic heterobinuclear ion pairs of the type [LNNiII(μ-Cl)2AlRCl]+[A]– (where R = Et or Me, [A]- = counter anion) have been observed in the catalyst systems LNNiIIBr2/Al2Et3Cl3 and LNNiIIBr2/Al2Me3Cl3. At room temperature, both ion pairs gradually transform into EPR-active complexes of Ni(I). Their possible role in ethylene polymerization is discussed.
- Ethylene intermediates
- CHAIN-WALKING POLYMERIZATION
- ETHYLENE POLYMERIZATION BEHAVIOR
- COMPLEXES SYNTHESIS