Unprecedented isospecific 3,4-polymerization of isoprene by cationic rare earth metal alkyl species resulting from a binuclear precursor.
Unprecedented isospecific 3,4-polymerization of isoprene by cationic rare earth metal alkyl species resulting from a binuclear precursor.
复制标题
DOI：
10.1021/ja055397r
复制
发表时间：
2005-09
影响因子：
15
通讯作者：
Lixin Zhang;Yi Luo;Z. Hou
中科院分区：
文献类型：
--
作者：
Lixin Zhang;Yi Luo;Z. Hou
通过使用双核稀土金属二烷基络合物如[Me 2 Si（C 5 Me 4）（μ-PCy）YCH 2 SiMe 3]2（Cy =环己基）和等摩尔量的[Ph 3 C][B（C 6 F 5）4]的组合作为催化剂体系，首次实现了异戊二烯的等规3，4-聚合。DFT计算表明，双核单阳离子单烷基物种，如[Me 2Si（C5 Me 4）（mu-PCy）Y（mu-CH 2SiMe 3）Y（mu-PCy）（C5 Me 4）SiMe 2]+，其中烷基桥接两个金属中心，可能是真正的催化剂物种。
The isospecific 3,4-polymerization of isoprene has been achieved for the first time by use of a combination of a binuclear rare earth metal dialkyl complex, such as [Me2Si(C5Me4)(mu-PCy)YCH2SiMe3]2 (Cy = cyclohexyl), and an equimolar amount of [Ph3C][B(C6F5)4] as a catalyst system. A DFT calculation suggested that a binuclear monocationic monoalkyl species, such as [Me2Si(C5Me4)(mu-PCy)Y(mu-CH2SiMe3)Y(mu-PCy)(C5Me4)SiMe2]+, in which the alkyl group bridges the two metal centers, could be the true catalyst species.