Synthesis and characterization of iron and cobalt dichloride bearing 2-quinoxalinyl-6-iminopyridines and their catalytic behavior toward ethylene reactivity

Iron-Based and Cobalt-Based Olefin Polymerisation Catalysts

“…While the 2,6-bis(imino)pyridine ligand frame has continued to lead the way, the past 10 years has also seen the development of alternative ligand sets that can act as compatible supports for iron and cobalt ethylene oligomerisation/polymerisation catalysts ( Table 4 ) [46,50,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,208,209] ; active catalysts based on bimetallic iron and cobalt precatalysts have also started to emerge ( Table 5 ) [54,210,211,212,213,214,215] . In the main, these systems show lower activities than the prototype bis(imino)pyridine-based catalysts, although several of these systems have significantly started to approach their catalytic performances (e.g.…”

Nickel(II) complexes chelated by 2-quinoxalinyl-6-iminopyridines: Synthesis, crystal structures and ethylene oligomerization

“…The compounds used as ligands L1-L6 were efficiently synthesized according to our reported procedure [18]. The dichloride nickel complexes (1-6) were synthesized by reactions of NiCl 2 AE 6H 2 O with the ligands L1-L6 in ethanol (Scheme 1).…”

“…In furtherance of our research in this field, synthesis and ethylene reactivity study of new metal halides bearing 2-quinoxalinyl-6-iminopyridine analogues with various ortho-positioned substituents on the aryl ring is being embarked upon. Their iron complexes gave good catalytic activities for ethylene reactivity (oligomerization and polymerization) upon activation with methylaluminoxane (MAO), while their cobalt analogues showed moderate activities toward ethylene oligomerization with modified methylaluminoxane (MMAO) [18]. Successively, the nickel analogues were synthesized and characterized.…”

2‐Benzoxazolyl‐6‐[1‐(arylimino)ethyl]pyridyliron(II) Chlorides as Ethylene Oligomerization Catalysts

“…[12] We recently reported several alternative iron complexes as catalysts for ethylene oligomerization and polymerization. [13] Iron complexes bearing 2-ester-6-iminopyridines showed moderate activities, [14] whereas complexes ligated by 2-imino-1,10-phenanthrolines (Figure 1, A), [15] 2-benzimidazolyl-6-iminopyridines (B), [16] 2-benzimidazolyl-1,10-phenanthroline (C), [17] 2-quinoxalinyl-6-iminopyridines (D), [18] N-[(pyridin-2-yl)methylene]quinolin-8-amines (E), [19] and 2-oxazoline/benzoxazole-1,10-phenanthrolines [20] (F) as pyramid. Upon activation with modified methylaluminoxane, all iron complexes showed moderate to good activities [up to ca.…”