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...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.展开更多
基金Project supported by the Program for New Century Excelleni Talents in University （No. NCET-07-0142）, the Program for New Century Excellent Talents in Heilongjiang Provincial University （No. NCET-06-010）, the National Natural Science Foundation of China （No. 20972025） and the Science Foundation of Tianjin University of Science ＆ Technology （No. 20090420）.
文摘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.
