RIKEN Advanced Science Institute, Wako, Saitama 351-0198 Japan.
Nat Chem. 2010 Apr;2(4):257-68. doi: 10.1038/nchem.595. Epub 2010 Mar 24.
This Review gives an overview on recent progress in the synthesis and chemistry of rare-earth metal dialkyl complexes bearing monoanionic ancillary ligands, with an emphasis on novel polymerization catalysts. These structurally well-defined and highly reactive compounds are prepared either by alkane elimination reactions between trialkyl rare-earth complexes and acidic neutral ligands, or by the metathetical reactions of rare-earth trihalides with the alkali metal salts of the corresponding ligands. On treatment with an appropriate borate compound, the dialkyl complexes are converted into the corresponding cationic monoalkyl species, which serve as excellent catalysts for the polymerization and copolymerization of a variety of olefins to yield a series of new polymer materials that exhibit novel properties. Alternatively, hydrogenation of the dialkyl rare-earth complexes with H(2) affords a new class of rare-earth polyhydride complexes with unique features in terms of both their structure and reactivity.
这篇综述概述了近年来合成和化学方面的最新进展，涉及含有单价阴离子辅助配体的稀土金属二烷基配合物，重点介绍了新型聚合催化剂。这些结构明确且高反应性的化合物可通过三烷基稀土配合物与酸性中性配体之间的烷烃消除反应，或通过稀土三卤化物与相应配体的碱金属盐之间的复分解反应来制备。用适当的硼酸化合物处理后，二烷基配合物转化为相应的阳离子单烷基物种，它们是聚合和共聚各种烯烃的优异催化剂，可得到一系列具有新颖性能的新型聚合物材料。或者，用氢气对二烷基稀土配合物进行加氢反应，得到一类新型的稀土多氢化物配合物，它们在结构和反应性方面具有独特的特点。
