Lanthanide Metallocene Reactivity with Dialkyl Aluminum Chlorides: Modeling Reactions Used to Generate Isoprene Polymerization Catalysts
Lanthanide Metallocene Reactivity with Dialkyl Aluminum Chlorides: Modeling Reactions Used to Generate Isoprene Polymerization Catalysts
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DOI：
10.1021/om049484o
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发表时间：
2005-01
期刊：
影响因子：
2.8
通讯作者：
W. Evans;Timothy M. Champagne;Dimitri Giarikos;J. Ziller
中科院分区：
文献类型：
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作者：
W. Evans;Timothy M. Champagne;Dimitri Giarikos;J. Ziller
利用三价[(C5Me5)2Ln]+配合物的良好配位环境，研究了镧系羧酸盐和R2AlCl （R = Me, Et, iBu）组分在制备镧系二烯聚合催化剂中的反应化学性质。在与[(C5Me5)2Sm(O2CC6H5)]2的反应中，每一种R2AlCl试剂都可以用氯化物取代羧酸盐配体，但不是像[(C5Me5)2SmCl]3那样形成简单的氯化物配合物，而是通过配体重分配生成双金属镧系铝二氯配合物（C5Me5）2Sm(μ-Cl)2AlR2。这些二（氯）桥接配合物也很容易由二价前体（C5Me5）2Sm(THF)2和R2AlCl形成。然而，（C5Me5）2Sm(THF)2和Et3Al之间的类似反应得到（C5Me5）2Sm(THF)(μ-η -Et)AlEt3，其中包含第一个Ln(III)−(η -Et)键，这是区分Et和Me的配位模式。为了确定混合单氯/烷基桥接（C5Me5）2Ln(μ-Cl)(μ-R)AlR2配合物是否可以分离，（C5Me5）2Y(μ-Cl)YCl(…
The well-defined coordination environment of trivalent [(C5Me5)2Ln]+ complexes has been used to examine the reaction chemistry of the lanthanide carboxylate and R2AlCl (R = Me, Et, iBu) components used in the preparation of lanthanide-based diene polymerization catalysts. Each of the R2AlCl reagents can replace a carboxylate ligand with chloride in reactions with [(C5Me5)2Sm(O2CC6H5)]2, but instead of forming a simple chloride complex like [(C5Me5)2SmCl]3, bimetallic lanthanide aluminum dichloro complexes (C5Me5)2Sm(μ-Cl)2AlR2 are generated by ligand redistribution. These bis(chloride)-bridged complexes are also readily formed from the divalent precursor (C5Me5)2Sm(THF)2 and R2AlCl. However, the analogous reaction between (C5Me5)2Sm(THF)2 and Et3Al gives (C5Me5)2Sm(THF)(μ-η2-Et)AlEt3, which contains the first Ln(III)−(η2-Et) linkage, a coordination mode that differentiates Et from Me. To determine if mixed mono-chloride/alkyl-bridged (C5Me5)2Ln(μ-Cl)(μ-R)AlR2 complexes can be isolated, (C5Me5)2Y(μ-Cl)YCl(...