New α-diimine nickel complexes—Synthesis and catalysis of alkene oligomerization reactions

Recent advances in Ni-mediated ethylene chain growth: Nimine-donor ligand effects on catalytic activity, thermal stability and oligo-/polymer structure

“…In comparison with unsymmetrical 17b, 18a and 18b ( In an attempt to balance more effectively good thermal stability with high activity we have investigated pre-catalysts containing ortho-substituted difluorobenzhydryl-substitution on both (21) As is evident from the above, fine tuning of the structural features of the pre-catalyst can not only affect the activity and thermal stability of the catalyst but it can also influence the microstructures and properties of the resulting polyethylenes. Tables 1 and 2 collect together some reported polymer data for a series of polyethylenes obtained under comparable polymerization conditions, using a set of structurally distinct unsymmetrical Complex 25b produced an active species that exhibits no regioselectivity, whereas using 25a some preference for primary insertion was observed [80].…”

Polymerization and Copolymerization Reactions of Light Alkenes with Postmetallocene Catalysts Containing Titanium Complexes with Bidentate Pinacol Ligands

“…As we described earlier, the efficacy of the Al(C 2 H 5 ) 2 Cl/Mg(C 4 H 9 ) 2 combination in converting various transition metal compounds into alkene polymerization catalysts can be explained by the generation of highly dispersed MgCl 2 : …”

“…The complexes were activated with a binary organometallic cocatalyst Al(C 2 H 5 ) 2 Cl ‐ Mg(C 4 H 9 ) 2 . As we reported earlier, combinations of organoaluminum compounds AlR 2 Cl and organomagnesium compounds MgR′ 2 , when used at an [Al]:[Mg] molar ratio above 2, are universal cocatalysts for all types of transition‐metal polymerization catalysts, including common heterogeneous and supported Ti‐based Ziegler‐Natta catalysts, Ti(OR) 4 ‐type compounds, metallocene complexes, and several post‐metallocene catalysts . These binary cocatalysts are also used for activation of Ni‐ and Ti‐based complexes in alkene oligomerization reactions .…”

Ethylene polymerization and copolymerization reactions with Ti(OR)4 – Al2(C2H5)3Cl3/Mg(C4H9)2 catalyst

“…8 We found earlier that combinations of chloro-organoaluminium compounds AlR 2 Cl and organomagnesium compounds MgR 0 2 , when used at an [Al]:[Mg] molar ratio above 2, are universal cocatalysts for converting various types of transition metal compounds into alkene polymerization catalysts, including TiCl 4 , 9,10 common heterogeneous and supported Ti-based catalysts, 11 metallocene complexes 12 and many post-metallocene complexes. [11][12][13][14][15][16][17] We reported recently that the Al(C 2 H 5 ) 2 Cl/Mg(C 4 H 9 ) 2 combination also converts Ti(Oiso-C 3 H 7 ) 4 into a very effective catalyst suitable for polymerization of both ethylene 7 and propylene. 18 We expected that a replacement of Al(C 2 H 5 ) 2 Cl in this ternary catalyst system with its analog, ethylaluminium sesquichloride Al 2 (C 2 H 5 ) 3 Cl 3 , will produce similar results.…”

“…We found earlier that combinations of chloro‐organoaluminium compounds AlR 2 Cl and organomagnesium compounds MgR′ 2 , when used at an [Al]:[Mg] molar ratio above 2, are universal cocatalysts for converting various types of transition metal compounds into alkene polymerization catalysts, including TiCl 4 , 9,10 common heterogeneous and supported Ti‐based catalysts, 11 metallocene complexes 12 and many post‐metallocene complexes 11–17 …”