摘要
4-R1 -6-R-2 -Me4 Cp H-Ph OH[R1 =t Bu,R=t Bu(1 ) ;R1 =H,R=t Bu(2 ) ,Ph(3 ) ,Me(4 ) ]经双三甲基硅基化后与 Ti Cl4 反应 ,合成了 4种限制几何构型茂金属催化剂 4-R1 -6-R-2 -Me4 Cp-Ph OTi Cl2 [R1 =t Bu,R=t Bu(5 ) ;R1 =H,R=t Bu(6) ,Ph(7) ,Me(8) ],合成产率有较大提高 .这些茂金属化合物经过 i Bu3Al和Ph3C+ B(C6 F5) - 4活化后对乙烯聚合有很好的催化活性 ,并生成乙基支化聚乙烯 .考察了催化剂结构与活性的关系以及聚合反应条件对催化剂性能的影响 。
Four constrained geometry tetramethylcyclopentadienyl-phenoxytitanium dichlorides 4-R_1-6-R-2-Me_4Cp-PhOTiCl_2[R_1= tBu, R= tBu(5); R_1=H, R= tBu(6), Ph(7), Me(8)] were successfully prepared from the reaction of TiCl_4 with the corresponding trimethylsilyl-functionalized ligands, which was obtained by treating the ligands 4-R_1-6-R-2-Me_4CpH-PhOH[R_1= tBu, R= tBu(1); R_1=H, R= tBu(2), Ph(3), Me(4)] with nBuLi and Me_3SiCl subsequently. The yields are higher than those previously reported. When activated with iBu_3Al and Ph_3C+B(C_6F_5)-_4, complexes 5—8 exhibit a reasonable catalytic activity for ethylene polymerization, producing ethyl branched polyethylenes. Influences of the molecular structure of these complexes and polymerization conditions on their catalytic properties were studied. Polyethylenes obtained with these catalysts were characterized.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第3期571-574,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金 (批准号 :2 0 3 740 2 3和 2 973 414 3 )资助 .
关键词
茂金属催化剂
烯烃聚合反应
单茂钛化合物
均相催化
Metallocene catalysts
Olefin polymerization
Monocyclopentadienyl titanium complex
Homogeneous catalysis
