Ethylene olipnerization hss been investisad by lsins catalyst metals into highly selective catalysts for ethylene oligomerization to low carbon linear a-olefins ( 6-Clo) . 8 * 9 Since an acute shortage of C, and Ca linear aolefins in our country, in recent years we are interested in the process of ethylene oligornenzation by transition metal catalysts.
Iron(I1) and cobalt(I1) diimine complexes in combination with a cocatalyst of ethvlaluminoxme ( FAO) for composed d i a ( n ) diimine ex^ (m = embihmd, N , N'-ethylenebisbenzal) and e t h y h n b m n e (EAo). The main p * in tduene and at ll,-,-m were defins A& low & "umbers ( G-c,). of reaction temperature, AVNi molar ratio and reaction period an both the catalytic activity and product distriitian were ex-P l o d . % g of d w r / ( m l ~ ' h ) ' ' to), N , K-o-ph-yl-N , K-o-ph@= bk( salicylidenearmna of 1-84 with m*4% of se'ectiviQ to ' 4-' 10 0 -9 wsf attained at 200 "c in the reaction when a catalyst composed d Ma-ethylene oligomerization were previously investigated in our laboratory, which show moderate activities with satisfying selectivity to G-Clo olefins.lo*'l ~n oder to make (PhCH=o-NG&N=CHPh) andEAOwa~used. Keywords ethylene oligomriz&n, nickel complex, diimine a systematic comfison* the catalytic Properti-of an&-Iigand g o y Ni(I1)-based diimine complexes, Ni(salphen) [ A , salphen = N , N'-o-phenylenebis ( salicylideneaminato 3 , NiCl2( PhCH = o-NC&&N = CHPh) (B) and NiClz( PhCH = NCHzCH2N = CHPh) (C) (Scheme 1). with EAO as cocatalyst for ethylene oligomerization have been explored at various reaction temperature and AVNi molar ratios, as well as different reaction periods. The experimental results show that the in-sh generated Ni( II)-based catalysts activated by EAO have moderate catalytic activities with high selectivity to low-carbon olefins and good selectivity to linear a -0lefins.