中文摘要：

向 1-hexene 的乙烯 trimerization 有 2,5-dimethylpyrrole (2,5-DMP ) 的催化系统 /Cr (III )/alkylaluminum/tetrachloroethane (TCE ) 被调查。在催化活动和产品选择的各种各样的 cocatalysts 的效果被讨论。结果证明 triethylaluminum (茶) ， trimethylaluminum (TMA ) ， tri-n-hexylaluminum (TNHA ) 和 tri-isobutylaluminum (TIBA ) 都是为向 1-hexene 的乙烯 trimerization 的有效 cocatalysts。2,5-DMP/Cr (III )/TEA/TCE 催化系统为乙烯 trimerization 负担得起最好的结果，当减少副产品的水平时形成。有在催化周期的活跃 Cr 种类的 alkylaluminum 的一些特定的相互作用模式被建议在催化活动和 1-hexene 选择解释 cocatalyst 的效果。

英文摘要：

Ethylene trimerization toward 1-hexene catalytic system with 2,5-dimethylpyrrole （2,5-DMP）/Cr（III）/alkylaluminum/tetrachloroethane （TCE） was investigated. The effects of various cocatalysts on catalytic activity and product selectivity were discussed. The results showed that triethylaluminum （TEA）, trimethylaluminum （TMA）, tri-n-hexylaluminum （TNHA） and tri-isobutylaluminum （TIBA） were all effective cocatalysts for ethylene trimerization toward 1-hexene. 2,5-DMP/Cr（III）/TEA/TCE catalytic system afforded the best results for ethylene trimerization, while reducing the level of by-product formation. Some specific interaction modes of alkylaluminum with active Cr species in the catalytic cycle were proposed to explain the effect of cocatalyst on catalytic activity and 1-hexene selectivity.