Synthesis of Novel Structure Based Low Generation Branched Salicylaldimine Nickel Complexes and Their Catalysis of Ethylene Oligomerization. Issue 37 (5th October 2018)

• Record Type: Journal Article
• Authors: Zhang, Na; Fu, Zijian; Jiang, Yan; Guo, Daizong; Chen, Liduo; Wang, Jun
• Is Part Of: ChemistrySelect. Volume 3:Issue 37(2018)
• Page Start: 10428
• Page End: 10433
• Publication Date: 2018-10-05
• Subjects: Ethylene oligomerizatio -- Nickel comple -- One-pot metho -- Reaction conditions; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201802164
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: A series of salicylaldimine nickel complexes bearing low generation branched molecules with naphthenic, straight and branched chain as cores have been synthesized by one‐pot method in high yield and were characterized by NMR spectroscopy, infrared spectroscopy, mass spectrometry and elemental analysis. The complexes C1‐C3 could form active catalysts in ethylene oligomerization reactions upon activation with co‐catalyst methylaluminoxane (MAO), triethylaluminium (AlMe3 ), ethylaluminum sesquichloride (EASC), AlEtCl2 or AlEt2 Cl. The catalytic performance was affected by reaction conditions such as reaction temperature, ethylene pressure, Al/Ni molar ration and reaction time. The catalytic activity could reach up to 10 5 oligomer mol −1 (Ni) h −1 and the products were C4, C6, C8 and trace higher carbon olefins (C10 ‐C18 ) under the optimum reaction conditions. When AlEt3 was used as co‐catalyst, the major product was C4 olefin. However the tandem reaction of ethylene oligomerization and Friedel‐Crafts occurred as chlorinated alkylaluminum reagents were used as co‐catalyst. In addition, the catalytic result showed that the kind of substituent groups in cores of branched salicylaldimine nickel complexes had a significant effect on the catalytic activity, and the distribution of ethylene oligomerization products was affected by co‐catalyst and solvent. Abstract : A series of novel low generation branched salicylaldimine nickel complexes were synthesized and characterized by IR, 1 H NMR, MS and elemental analysis. Upon activiation with co‐catalyst, the nickel complexes displayed better catalytic performance for ethylene oligomerization. Under the optimum reaction conditions, the catalytic activity could reach up to 10 5 oligomer mol −1 (Ni) h −1 and the products were C4, C6, C8 and trace higher carbon olefins (C10 ‐C18 ) with toluene as solvent and MAO as co‐catalyst.