Ethylene Oligomerization Study Bearing Nickel (II) and Cobalt (II) Complexes with N, O‐Donor Schiff Bases as Ligands. Issue 47 (18th December 2019)

• Record Type: Journal Article
• Authors: Liu, Jinyi; Wang, Jun; Chen, Liduo; Zhang, Na; Lan, Tianyu; Wang, Libo
• Is Part Of: ChemistrySelect. Volume 4:Issue 47(2019)
• Page Start: 13959
• Page End: 13963
• Publication Date: 2019-12-18
• Subjects: Schiff bases -- Nickel complex -- Cobalt complex -- Ethylene oligomerization; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201903599
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: A series of novel nickel 1–4 {[Ni(L1 )] (1 ); [Ni(L2 )Cl2 ] (2 ); [Ni(L3 )Cl2 ] (3 ); [Ni(L4 )Cl2 ] (4 )} and cobalt complexes 5–8 {[Co(L1 )] (5 ); [Co(L2 )Cl2 ] (6 ); [Co(L3 )Cl2 ] (7 ); [Co(L4 )Cl2 ] (8 )}bearing N, O‐donor Schiff bases as ligands L1‐L4 (L1 = (E)‐2‐(((2‐phenoxyethyl)imino)methyl)‐phenol; L2 = (E)‐5‐methoxy‐2‐(((2‐phenoxyethyl)imino)methyl)phenol; L3 = (E)‐2‐(((2‐(2‐methox yphenoxy)ethyl)imino)methyl)phenol; L4 = (E)‐5‐methoxy‐2‐(((2‐(2‐methoxyphenoxy)ethyl)imino) methyl)phenol) were synthesized from the complex reaction between salicylaldehyde and phenoxye‐thylamine analogues and characterized by UV‐Vis, IR, 1 H NMR, ESI‐MS and elemental analysis. All the nickel complexes (1‐4 ) and cobalt complexes (5‐8 ) as catalyst precursors were evaluated in detail with methylaluminoxane (MAO) as an activator in the ethylene oligomerization. At the same time, the effects of reaction parameters, catalyst structures and solvent on ethylene oligomerization were investigated too. As a result, complexes 5–8 showed a better catalytic activity (2.05‐3.38×10 5 g/(mol(Co)h) and a higher selectivity of 34.44% toward the valuable C8 compound using toluene as the solvent than complexes 1–4 . Abstract : A series of salicylaldehyde ligands, nickel complexes and cobalt complexes were synthesized, characterized and studied as catalysts for ethylene oligomerization. All synthesized complexes exhibited excellent catalytic properties for ethylene oligomerization. Meanwhile, the synthesized cobalt complex possessed the better catalytic activity and selectivity for high carbon number olefins, compared with nickel complexes with toluene as solvent.