Synthesis and Characterisation of Tetranuclear Ruthenium Polyhydrido Clusters with Pseudo-Tetrahedral Geometry
Synthesis and Characterisation of Tetranuclear Ruthenium Polyhydrido Clusters with Pseudo-Tetrahedral Geometry
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伪四面体四核钌多氢化团簇的合成与表征
DOI：
10.1039/c6dt04523e
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Toshiro Takao
中科院分区：
文献类型：
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作者：
Hajime Kameo;Yutaka Ito;Ryuichi Shimogawa;Asuka Koizumi;Hiroki Chikamori;Junko Fujimoto;Hiroharu Suzuki;Toshiro Takao
双核四氢化钌（Cp Ru）2（μ-H）4（1）与过量的Brønsted酸（如HBF 4·OEt 2）在甲苯中反应，得到了具有四面体构型的双核八氢化钌[（Cp Ru）4 H8]2+（5）.通过在环境温度下将稀酸滴加到剧烈搅拌的1的溶液中获得单阳离子七氢化四钌[（Cp*Ru）4 H7]+（7）。通过用甲醇钠或氢化钠处理，将Dication 5以高产率转化为单阳离子七氢配合物7。在四氢呋喃（THF）中用LiAlH 4处理5，可以高效地将5直接转化为中性六配位络合物（Cp*Ru）4 H6（8）。5到8的转化是可逆的，并且将布朗斯台德酸加入到8中通过形成中间体7得到5。1在THF中于70 ℃加热直接得到四核配合物8。配合物8′和四氢化四钌（CpEtRu）4 H4（10′）（其中8′和10′具有η5-C5 EtMe 4配体而不是Cp* 配体）通过消除/加成氢相互关联。通过X射线衍射确定了5、7、8和10′的结构，并通过密度泛函理论（DFT）对Cp* 配体的甲基被氢原子取代的模型化合物进行了计算，讨论了Ru 4的核心结构和配位模式.
Dicationic tetranuclear ruthenium octahydride [(Cp*Ru)4H8]2+ (5) with tetrahedral geometry was obtained by reaction of dinuclear ruthenium tetrahydride (Cp*Ru)2(μ-H)4 (1) with an excess of Brønsted acids, such as HBF4·OEt2, in toluene. Monocationic tetraruthenium heptahydride [(Cp*Ru)4H7]+ (7) was obtained by dropwise addition of a diluted acid to a rigorously stirred solution of 1 at ambient temperature. Dication 5 was converted into monocationic heptahydrido complex 7 in high yield by treatment with sodium methoxide or sodium hydride. The direct conversion of 5 into neutral hexahydrido complex (Cp*Ru)4H6 (8) was achieved in a highly efficient manner by treating 5 with LiAlH4 in tetrahydrofuran (THF). The conversion of 5 into 8 was reversible, and the addition of a Brønsted acid to 8 gave 5via the formation of 7 as an intermediate. Tetranuclear complex 8 was directly obtained from 1 by heating it in THF at 70 °C. Complex 8′ and tetraruthenium tetrahydride (CpEtRu)4H4 (10′), where 8′ and 10′ possessed η5-C5EtMe4 ligands instead of Cp* ligands, were mutually related by the elimination/addition of dihydrogen. The structures of 5, 7, 8, and 10′ were determined by X-ray diffraction, and the Ru4 core structure and the coordination mode of hydrido ligands were discussed based on density functional theory (DFT) calculations for model compounds where the methyl groups of Cp* ligands were replaced with hydrogen atoms.