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首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >Bis('ferrocene-saliminato') group 4 metal complexes: synthesis, structural features and use in homogenous Ziegler-Natta polymerization catalysis
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Bis('ferrocene-saliminato') group 4 metal complexes: synthesis, structural features and use in homogenous Ziegler-Natta polymerization catalysis

机译：Bis（“二茂铁-saliminato”）第4组金属配合物：合成，结构特征及其在均相Ziegler-Natta聚合催化中的用途

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摘要

Reaction of the (p-S) enantiomers of the N-aryl-substituted planar chiral alpha-hydroxy-ferrocene carbaldimines [(p-S)-3 (aryl = 2,6-diisopropylphenyl (a), -C6F5 (c)] with LDA gave the corresponding lithiated "ferrocene-saliminato" systems (p-S)-4a and (p-S)-4c, respectively. Both were characterized by X-ray diffraction. In the crystal, compound (p-S)-4a features an associated cyclotrimeric structure with a six-membered alternating Li3O3 core while (p-S)-4c shows a cyclotetrameric structure around a central cubic Li4O4 core unit. The reagent (p-S)-4a was treated with the group 4 metal tetrahalides to yield the bis(ferrocene-saliminato)MCl2 complexes 5a (Ti), 6a (Zr), and 7a (Hf). In the crystal the latter feature single diastereomeric octahedral (p-S,p-S,Lambda)-6a (Zr) and (p-S,p-S,Lambda)-7a (Hf) structures, whereas the titanium analogue shows both the (p-S,p-S,Lambda)-5a and the (p-S,p-S,Lambda)-5a diastereoisomers in the crystal. Upon dissolving, we observe a rapid Lambda-5a to Lambda-5a isomerization to occur. The latter is the only isomer observed in solution under thermodynamic control. In contrast, the pure Lambda-6a and Lambda-7a isomers equilibrate in solution with a second isomer to a ca. 1 : 1 mixture. Treatment of (p-S)-4c (aryl = C6F5) with TiCl4 or ZrCl4 gave the analogous octahedral complexes 5c and 6c, respectively, as single diastereoisomers. Treatment of the neutral ferrocene-salimines (p-S)-3a-c with ZrCl4 or HfCl4 gave the respective N-aryl-substituted zwitterionic (ferrocene-salimine)(2)MCl4 complexes (8a: Zr, 2,6-diisopropylphenyl; 9a: Hf, 2,6-diisopropylphenyl; 8b: Zr, mesityl; 8c: Zr, C6F5), that contain the zwitterionic iminium-tautomers O-bonded to the metal. Activation of a variety of the complexes 5-7 and 8 with methylalumoxane gave homogeneous ethylene polymerization catalysts that exhibit low to moderate catalyst activities in the 20 degrees C to 125 degrees C temperature range.
机译：N-芳基取代的平面手性α-羟基二茂铁二胺[（pS）-3（芳基= 2,6-二异丙基苯基（a），-C6F5（c）]）的（pS）对映体与LDA的反应相应的锂化的“二茂铁-saliminato”系统（pS）-4a和（pS）-4c均通过X射线衍射表征。在晶体中，化合物（pS）-4a具有相关的环三聚体结构，具有六价（pS）-4c在中心立方立方Li4O4核心单元周围显示环四聚体结构。（pS）-4a用4组金属四卤化物处理，得到双（二茂铁-盐酸盐）MCl2络合物5a（ Ti），6a（Zr）和7a（Hf）在晶体中具有单非对映八面体（pS，pS，Lambda）-6a（Zr）和（pS，pS，Lambda）-7a（Hf）结构，而钛类似物在晶体中同时显示（pS，pS，Lambda）-5a和（pS，pS，Lambda）-5a非对映异构体。溶解后，我们观察到快速的Lambda-5a转变为Lam bda-5a发生异构化。后者是在热力学控制下在溶液中观察到的唯一异构体。相比之下，纯的Lambda-6a和Lambda-7a异构体在溶液中与第二个异构体平衡为大约一个。 1：1混合物。用TiCl4或ZrCl4处理（p-S）-4c（芳基= C6F5），分别得到相似的八面体络合物5c和6c，为单一非对映异构体。用ZrCl4或HfCl4处理中性二茂铁盐胺（pS）-3a-c得到相应的N-芳基取代的两性离子（二茂铁盐胺）（2）MCl4复合物（8a：Zr，2,6-6-diisopropylphenyl; 9a： Hf，2，6-二异丙基苯基; 8b：Zr，均三甲苯基; 8c：Zr，C6F5），其包含与金属键合的两性离子亚胺-互变异构体。用甲基铝氧烷活化多种配合物5-7和8，得到均相的乙烯聚合催化剂，该催化剂在20℃至125℃的温度范围内具有低至中等的催化剂活性。

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