Abstract
A direct one-pot assembly has been utilized for the preparation of 2-imino-6,7-dihydroquinlin-8(5H)-imine-ferrous chloride complexes, [2-(ArN[double bond, length as m-dash]CCH(3))-8-(ArN)C(9)H(8)N]FeCl(2) (Ar = 2-Me-4-(CHPh(2))-6-(C(5)H(9))C(6)H(2)Fe1, 2-Me-4-(C(5)H(9))-6-(CHPh(2))C(6)H(2)Fe2, 2-(C(5)H(9))-4-Me-6-(CHPh(2))C(6)H(2)Fe3, 2-(C(5)H(9))-4,6-(CHPh(2))(2)C(6)H(2)Fe4, 2-(C(6)H(11))-4,6-(CHPh(2))(2)C(6)H(2)Fe5, 2-(C(8)H(15))-4,6-(CHPh(2))(2)C(6)H(2)Fe6, 2-F-4,6-(CHPh(2))(2)C(6)H(2)Fe7, 2-Cl-4,6-(CHPh(2))(2)C(6)H(2)Fe8], disparate in the steric/electronic profile of their N-aryl groups. In addition to spectroscopic characterization, the structural properties of representative Fe3 and Fe5 have been determined by single crystal XRD. Under activation with MAO or MMAO, Fe1-Fe8 displayed very high catalytic activities for ethylene polymerization at 60 °C [up to 25.20 × 10(6) g (PE) per mol (Fe) per h for Fe2/MMAO]; even at temperatures as high as 100 °C the activity remained high [3.92 × 10(6) g (PE) per mol (Fe) per h]. Notably, the polymers generated using MMAO as activator showed distinctly lower molecular weight than those with MAO [M (w) range: 1.36-62.41 kg mol(-1) (MMAO) vs. 13.07-210.56 kg mol(-1) (MAO)], with ortho-cycloalkyl-containing Fe4-Fe6 forming polymers at the lowest end of the M (w) range and with the narrowest dispersity (M (w)/M (n) range: 1.6-2.3). Microstructural analysis of selected polymers highlighted the presence of both vinyl-terminated polymers and fully saturated polymers, the ratio of which could be influenced by not only the type of aluminum-alkyl activator but also by the run temperature and the N-aryl substitution pattern. Significantly, the molecular weights of many of these polyethylenes fall within the specification range for polyethylene waxes used in industrial applications.