6533b85cfe1ef96bd12bc14b

RESEARCH PRODUCT

Ethylene oligomerization with 2-hydroxymethyl-5,6,7-trihydroquinolinyl-8-ylideneamine-Ni(II) chlorides

Lei XuLei XuWen-hua SunXinquan HuJiaxin LiJiaxin LiZygmunt FlisakZygmunt FlisakYanping MaWenhua Lin

subject

Steric effectsEthyleneSubstituentInfrared spectroscopy010402 general chemistryCo-catalyst01 natural sciencesBiochemistryMedicinal chemistryInorganic ChemistryMetalchemistry.chemical_compoundSubstituent effectEthylene oligomerizationMaterials ChemistryHydroxymethylSelectivityPhysical and Theoretical ChemistryNickel complexes010405 organic chemistryChemistryLigandOrganic Chemistry0104 chemical sciencesActivityElemental analysisvisual_artvisual_art.visual_art_medium

description

Abstract A series of Ni complexes of the general formula [2-(MeOH)-8-{N(Ar)}C9H8N]NiCl2, where Ar = 2,6-Me2C6H3 in Ni1; 2,6-Et2C6H3 in Ni2; 2,6-i-Pr2C6H3 in Ni3; 2,4,6-Me3C6H2 in Ni4; 2,6-Et2-4-MeC6H2 in Ni5 and 2,4,6-t-Bu3C6H2 in Ni6 has been synthesized and characterized by elemental analysis and IR spectroscopy. On activation with MMAO or Et2AlCl, these complexes showed high activity in ethylene oligomerization, reaching 2.23 × 106 g·mol–1 (Ni) h–1 at 30 °C with the Al/Ni ratio of 5500 and 9.11 × 105 g·mol–1 (Ni) h–1 with the Al/Ni of 800, respectively. Moreover, the content of α-C4 indicated high selectivity exceeding 99% in the Ni/Et2AlCl system. Comparing with the previous report by our group, this work discloses higher activity, presumably due to the substituent at the 2-position within the ligand influencing the steric hindrance around the metal atom. Furthermore, it is worth noting that the branched alkenes have been observed (iso-C6: 35.3 – 57.2%) in the oligomerization products.

10.1016/j.jorganchem.2021.121720https://doi.org/10.1016/j.jorganchem.2021.121720