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New Polymerization Reactions by Dynamic Rare Earth Complexes

动态稀土配合物的新聚合反应

基本信息

批准号：
14078224
负责人：
HOU Zhaomin
金额：
$ 15.87万
依托单位：
RIKEN
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

1. Synthesis of Rare Earth Metal Bis(alkyl) Complexes and Conversion into Cationic Mono(alkyl) Active Species : Recently, considerable attention has been directed to rare earth metal bis(alkyl) complexes, since such complexes or cationic mono(alkyl) species prepared from them are expected to provide a sterically and electronically more unsaturated metal center and thus to show unique reactivity that differs from those of the conventional metallocenens. In this study, a series of half-sandwich rare earth metal bis(alkyl) complexes have been successfully prepared from Ln(CH_2SiMe_3)_3 (2thf) and C_5Me_4HSiMe_3. Binuclear rare earth metal bis(alkyl) complexes, in which the two metal centers are bridged by two phosphido ligands, and non-metallocene yttrium bis(alkyl) complexes have also been obtained in an analogous way. These bis(alkyl) complexes can be readily converted to the corresponding cationic mono(alkyl) species by treating with 1 equiv of [Ph_3C][B(C_6F_5)_4].2. Development of Hi … More ghly Selective Copolymerization Reactions Catalyzed by Cationic Rare Erath Metal Mono(alkyl) Species : These cationic rare earth metal species can act as excellent catalysts for the region-and stereospecific polymerization and copolymerization of various olefins. They exhibit excellent activities and selectivity for syndiospecific copolymerization of styrene with ethylene, alternating copolymerization of ethylene with norbornene or dicyclopentadiene, and isospecific 3,4-polymerization and living cis-1,4-polymerization of isoprene. Most of these polymerization reactions are unique to the rare earth metal catalysts, and are difficult to achieve by previously known catalyst systems.3. Synthesis of Rare Earth Metal Hydride Clusters and Studies on Synergistic Reactivity of These Complexes : In the course of these studies, we found that the half-sandwich rare earth metal bis(alkyl) complexes can readily react with H_2 to afford the corresponding tetranuclear octahydrido complexes. These hydride clusters exhibit high reactivities towards various multiple bonds. For example, the reaction with carbon monoxide afforded selectively ethylene under mild conditions. Less

1.稀土金属双（烷基）络合物的合成和转化成阳离子单（烷基）活性物质：最近，相当多的注意力已经指向稀土金属双（烷基）络合物，因为这样的络合物或由它们制备的阳离子单（烷基）物质预期提供空间和电子上更不饱和的金属中心，因此显示出不同于常规双（烷基）络合物的独特反应性。本文以Ln（CH_2SiMe_3）_3（2 thf）和C_5Me_4HSiMe_3为原料，合成了一系列半夹心稀土金属双（烷基）配合物。双核稀土金属双（烷基）配合物，其中两个金属中心由两个膦配体桥接，和非茂金属钇双（烷基）配合物也已经以类似的方式获得。这些双（烷基）络合物可以通过用1当量的[Ph_3C][B（C_6F_5）_4]处理而容易地转化为相应的阳离子单（烷基）物种。Hi的发展 ...更多信息阳离子稀土金属单（烷基）物种催化的高选择性共聚反应：这些阳离子稀土金属物种可以作为各种烯烃的区域和立体定向聚合和共聚的优良催化剂。它们对苯乙烯与乙烯的间规共聚、乙烯与异戊二烯或双环戊二烯的交替共聚以及异戊二烯的等规3，4-聚合和活性顺式-1，4-聚合均表现出优异的活性和选择性。这些聚合反应中的大多数是稀土金属催化剂所特有的，并且难以通过先前已知的催化剂体系来实现。稀土金属氢化物簇合物的合成及其协同反应性的研究：在研究过程中，我们发现半夹心结构的稀土金属双（烷基）配合物可以很容易地与H_2反应生成相应的四核八氢配合物。这些氢化物簇对各种多重键表现出高反应性。例如，与一氧化碳的反应在温和条件下选择性地提供乙烯。少