Rare-Earth-Metal Allyl Complexes Supported by the [2-(N,N-Dimethylamino)ethyl]tetramethylcyclopentadienyl Ligand: Structural Characterization, Reactivity, and Isoprene Polymerization
Rare-Earth-Metal Allyl Complexes Supported by the [2-(N,N-Dimethylamino)ethyl]tetramethylcyclopentadienyl Ligand: Structural Characterization, Reactivity, and Isoprene Polymerization
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DOI：
10.1021/om500725g
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发表时间：
2015-01
期刊：
影响因子：
2.8
通讯作者：
Lars N. Jende;Christoph O. Hollfelder;C. Maichle‐Mössmer;R. Anwander
中科院分区：
文献类型：
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作者：
Lars N. Jende;Christoph O. Hollfelder;C. Maichle‐Mössmer;R. Anwander
通过两步盐复分解反应合成了含氨基官能化环戊二烯配体(CpNMe2=1-[2-(N，N-dimethylamino)ethyl]-2，3，4，5-tetramethylcyclopentadienyl)的稀土金属半三明治烯丙基配合物。用LiCpNMe2与LnCl3(THf)x反应，然后与格氏试剂C3H5MgCl反应，生成了双(烯丙基)半夹心配合物CpNMe2Ln(η3-C3H5)2，仅对较小的稀土金属(Ln=Y，Ho，Lu)以较高的产率(82-88%)合成。在较大钕的情况下，以68%的产率得到了二聚单(烯丙基)氯代半三明治配合物[CpNMe2Nd(η3-C3H5)(μ-Cl)]2。与有机硼酸盐[Ph3C][B(C6F5)4]和[PhNMe2H][B(C6F5)4]阳离子化后，所有配合物在异戊二烯聚合中表现出中等到高的活性，Y、Ho和Nd3个金属中心主要产生3，4-微结构(最高79%)。在CpNMe2Ln(η3-C3H5)2(Ln=Y，Ho)/[PhNMe2H][B(C6F5)4]和[CpNMe2ND(η3-C3H5)(μ.
Rare-earth-metal half-sandwich allyl complexes bearing an amino-functionalized cyclopentadienyl ligand (CpNMe2 = 1-[2-(N,N-dimethylamino)ethyl]-2,3,4,5-tetramethylcyclopentadienyl) were synthesized in a two-step salt-metathesis reaction. Treatment of LnCl3(THF)x with LiCpNMe2, followed by an in situ reaction with the Grignard reagent C3H5MgCl, generated the bis(allyl) half-sandwich complexes CpNMe2Ln(η3-C3H5)2 only for the smaller rare-earth metals (Ln = Y, Ho, Lu) in good yields (82–88%). In case of the larger neodymium, the dimeric mono(allyl) chlorido half-sandwich complex [CpNMe2Nd(η3-C3H5)(μ-Cl)]2 was obtained in 68% yield. All complexes show moderate to high activity in isoprene polymerization upon cationization with organoborates [Ph3C][B(C6F5)4] and [PhNMe2H][B(C6F5)4], the yttrium, holmium, and neodymium metal centers yielding mainly 3,4-microstructures (maximum 79%). Addition of 10 equiv of AlMe3 to the catalyst systems CpNMe2Ln(η3-C3H5)2 (Ln = Y, Ho)/[PhNMe2H][B(C6F5)4] and [CpNMe2Nd(η3-C3H5)(μ...