A comparative study of ethylene polymerization by bis(aminotropone) Ti catalysts

Titanium (IV) and Nickel (II) Catalysts Based on Anilinotropone Ligands

“…As could be predicted, as molar ratio of [Al]/[Ti] increased, activity of catalysts increased, but Mw values of resultant polymers decreased [19][20][21].…”

“…A slight increase in TOF was observed for the 2,6-diphenyl-substituted catalyst (17). Significant reduction in TOF was observed for the 2-methyl-6-t-Butyl (16), 2-methyl-(22), 2-t-Butyl-(15), and 2,3,4,5,6-pentafluoro-substituted (20) catalysts. Molecular weights generally increase with increasing steric bulk of the ortho substituents (Table 2) [62].…”

“…The large amount of hydrogen concentration could slightly increase the activity of the catalyst 1, 8 and 9 ( Figure 3) [20]. A reasonable explanation for this effect might be increase of homogeneity of polymerization system and return of catalytically less reactive species, such as those resulting from 2,1-insertions, to the catalytic cycle through their fast hydrogenation [20].…”

“…A reasonable explanation for this effect might be increase of homogeneity of polymerization system and return of catalytically less reactive species, such as those resulting from 2,1-insertions, to the catalytic cycle through their fast hydrogenation [20].…”

“…As a result of ligand-oriented catalyst design research, Sandaroos and coworkers [19][20][21] described the catalytic performance of new titanium complexes 1-9 containing aminotropone chelate ligands for ethylene polymerization (Scheme 1). The following subsections detail the results observed in these works.…”