Multinuclear palladium compounds containing palladium centers ligated by five silicon atoms
Multinuclear palladium compounds containing palladium centers ligated by five silicon atoms
复制标题
DOI：
10.1073/pnas.0700450104
复制
发表时间：
2007-05
期刊：
影响因子：
--
通讯作者：
S. Shimada;Yonghua Li;Y. Choe;Masato Tanaka;M. Bao;T. Uchimaru
中科院分区：
文献类型：
--
作者：
S. Shimada;Yonghua Li;Y. Choe;Masato Tanaka;M. Bao;T. Uchimaru
钯（Pd）通常优选低氧化态。到目前为止，还没有已知的具有+5氧化态的稳定的Pd化合物。在这里，我们报告了两个多核钯化合物含有钯中心连接的五个硅（Si）原子。[{1，2-C6 H4（SiMe 2）（SiH 2）}PdII（Me 2 PCH 2CH 2PMe 2）]（Me =甲基）的热缩合反应得到作为主要产物的双核PdII化合物和三核Pd化合物的两个立体异构体和作为次要产物的四核Pd化合物。四个Pd化合物的结构通过单晶X-射线结构分析证实。双核Pd化合物具有通过Si-Si单键连接的[{1，2-C6 H4（SiMe 2）（SiH）}PdII（Me 2 PCH 2CH 2PMe 2）]的二聚体结构，所述Si-Si单键通过两个分子的起始化合物的脱氢形成。三核和四核钯化合物的钯中心与五个硅原子以正常的Pd-Si单键距离键合。三核和四核Pd化合物的理论计算准确地再现了它们的X射线结构，并表明中心Pd原子的所有Pd-Si键具有相对较高的单键特征。
Palladium (Pd) generally prefers low oxidation states. So far, no stable Pd compound with a +5 oxidation state is known. Here, we report two multinuclear Pd compounds containing Pd centers ligated by five silicon (Si) atoms. A thermal condensation reaction of [{1,2-C6H4(SiMe2)(SiH2)}PdII(Me2PCH2CH2PMe2)] (Me = methyl) afforded two stereoisomers of dinuclear PdII compounds and a trinuclear Pd compound as major products and a tetranuclear Pd compound as a minor product. The structures of the four Pd compounds were confirmed by single-crystal x-ray structure analysis. The dinuclear Pd compounds have a dimeric structure of [{1,2-C6H4(SiMe2)(SiH)}PdII(Me2PCH2CH2PMe2)] connected through a Si–Si single bond formed by dehydrogenation of two molecules of the starting compound. The trinuclear and tetranuclear Pd compounds proved to have Pd centers bonded to five Si atoms with normal Pd–Si single-bond distances. Theoretical calculations of the trinuclear and tetranuclear Pd compounds accurately reproduced their x-ray structures and suggested that all of the Pd–Si bonds of the central Pd atoms have a relatively high single-bond character.