Methylene-Bridged Metallocenes with 2,2′-Methylenebis[1H-inden-1-yl] Ligands: Synthesis, Characterization, and Polymerization Catalysis of a Synthetically Simple Class ofC2- andC2v-Symmetricansa-Metallocenes
作者:Luigi Resconi、Isabella Camurati、Cristina Fiori、Davide Balboni、Pierluigi Mercandelli、Angelo Sironi
DOI:10.1002/hlca.200690154
日期:2006.8
7-dimethyl-1H-inden-1-yl]}zirconium ([ZrCl2(5′)] is the most open. The mixture [ZrCl2(1′)]/methylalumoxane (MAO) is inactive in the polymerization of both ethylene and propylene, while the metallocenes with substituted indenyl ligands polymerize propylene to atactic polypropylene of a molecular mass that depends on the size of the alkyl or aryl groups at the 1,1′ positions of the ligand. Ethene is polymerized
甲醛和1个之间的酸催化反应ħ茚,3-烷基-和3-芳基1 ħ -indenes,和六元环取代的1个ħ -indenes,用1个ħ茚/ CH 2 O比的2:1,在烃溶剂温度超过60°,收率2,2'-亚甲基双[1 ħ -indenes] 1 - 8在50-100%收率。这些2,2'-亚甲基双[1 H-茚]容易被2当量去质子化。通过用BuLi或MeLi的混合物制备相应的二锂盐,将其有效地转化为Zr和Hf的ansa-茂金属。未取代的二氯(1,1',2,2',3,3',3a,3'a,7a,7'a- η)-2,2'-亚甲基双[1 H-茚-1-基]}锆([ZrCl 2(1')])在有机溶剂中的溶解度最低。由于烃基取代基取代了1 H-茚基部分,增加了配合物的烃溶解性,并且在配体的1,1'位上存在大于Me基的取代基会给金属化步骤带来非对映选择性,因为仅获得外消旋异构体。亚甲基桥连“柄型-zirconocenes”示出了双明显开放排列[1