后过渡金属苊基α-双亚胺镍催化剂的合成及催化乙烯聚合

Synthesis and ethylene polymerization of acenaphthy-based nickel(Ⅱ)-α-diimine complexes

合成2种具有新型结构的苊二亚胺Ni催化剂[Ar N=C(Nap)-C(Nap)=NAr]Ni Br2(Ar=2,6-(i-Pr)2-phenyl,Nap=5-R-1,8-naphthdiyl;其中,Cat.A中R=H;Cat.B中R=OCH3),通过核磁氢谱分析(1H-NMR)及元素分析对其进行表征.同时,该催化剂也被用于乙烯聚合反应中,考察聚合体系的温度、铝镍比以及苊碳骨架上的取代基团对乙烯聚合反应活性的影响.研究结果表明:苊碳骨架上引入供电子取代基后催化剂的催化活性明显提高;当铝镍摩尔比为1 500时,2种新型Ni(II)催化剂的催化活性最高,氢取代的催化剂(Cat.A)在聚合温度为30℃时对乙烯的催化活性为371 kg/(mol·h),而甲氧基取代的催化剂(Cat.B)在10℃下对乙烯聚合的催化活性达到了446 kg/(mol·h).

Two α-diimine nickel complexes [Ar-N=C（Nap）-C（Nap）= N-Ar] NiBr2 with new structures [Ar=Ar=2,6-（i-Pr）2 -phenyl,Nap =5 -R -1,8 -naphthdiyl;Cat.A：R =H;Cat.B =OCH3] were synthesized successfully andcharacterized by the 1H-NMR analysis and elemental analysis. They were used to catalyse ethylene polymerization.The influences resulting from the changes of polymerization temperatures,the mole ratio of Al/Ni and the alkylsubstituents on backbone carbon of acenaphthene on the ethylene polymerization activities were investigated. Theresults showed that polymerization activities were improved significantly because of the introduction of electrondonating substituent on backbone carbon of acenaphthene. Especially,the catalytic system had the highest activitywhen Al/Ni equalled 1 500. The ethylene polymerization activities with Cat.A reached 371 kg/（mol.h）under thecondition 30 益and those reached 446 kg/（mol.h）under 10 ℃with Cat.B.