Photochemical Oxidative Addition of Germane and Diphenylgermane to Ruthenium Dihydride Complexes
Photochemical Oxidative Addition of Germane and Diphenylgermane to Ruthenium Dihydride Complexes
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DOI：
10.1021/acs.organomet.8b00770
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发表时间：
2019-02-11
期刊：
影响因子：
2.8
通讯作者：
Whitwood, Adrian C.
中科院分区：
文献类型：
--
作者：
Dickinson, David P.;Evans, Simon W.;Whitwood, Adrian C.
报道了日耳曼和二苯基日耳曼与Ru(PP)(2)H-2 （PP = R2PCH2CH2PR2或DuPhos， R = Ph dppe, R = Et depe, R = Me dmpe）的光化学反应。与GeH4反应生成Ru(PP)(2)(GeH3)H的顺式和反式异构体混合物，但DuPhos络合物仅以顺式形式生成产物。原位激光光解（355nm）表明，初始产物是顺式异构体，经过热异构化为反式异构体。络合物顺式-[Ru(dppe)(2)(GeH3)H]选择性结晶，可以测定其x射线结构为germyl氢化物，Ru-H中心点中心点中心点Ge的距离为2.64(3)埃，表明RuH和Ge之间不存在残留的相互作用。DFT计算结果也与完全氧化加成一致。顺式-[Ru(DuPhos)(2)(GeH3)H]的八面体结构显示出明显的畸变。晶体中的主要物质（95%）呈现出Ru-H中心点中心点中心点距离为2.42(5)埃的结构，表明这些中心之间的相互作用可以忽略不计。结构的DFT计算结果与实验结果一致。Ru(PP)(2)H-2与二苯基日耳曼的反应产顺式-[Ru(PP)(2)(GePh2H)H]]只在PP = dmpe和depe中发生，而在dppe中则以顺式异构体为主。Ru(dppe)(2)(H)(2)与两种底物Ph2SiH2和Ph2GeH2之间的光化学竞争反应导致Si- H和Ge-H氧化加成活化，并对germyhy化物产物产生动力学偏好（0.18:1）。在加热过程中观察到Ru(dppe)(2)(SiPh2H)H向Ru(dppe)(2)(GePh2H)H的热转化。
Photochemical reactions of germane and diphenylgermane with Ru(PP)(2)H-2 (PP = R2PCH2CH2PR2 or DuPhos, R = Ph dppe, R = Et depe, R = Me dmpe) are reported. Reaction with GeH4 generates a mixture of cis and trans isomers of Ru(PP)(2)(GeH3)H except for the DuPhos complex which yields the product only in the cis form. In situ laser photolysis (355 nm) demonstrates that the initial product is the cis isomer that undergoes thermal isomerization to the trans isomer. The complex cis-[Ru(dppe)(2)(GeH3)H] crystallizes selectively, allowing determination of its X-ray structure as a germyl hydride with a long Ru-H center dot center dot center dot Ge separation of 2.64(3) angstrom indicating that no residual interaction between the RuH and Ge is present. DFT calculations are also consistent with full oxidative addition. The structure of cis-[Ru(DuPhos)(2)(GeH3)H] reveals significant distortion from an octahedral geometry. The major species in the crystal (95%) exhibits a structure with a Ru-H center dot center dot center dot Ge distance of 2.42(5) angstrom suggesting negligible interaction between these centers. DFT calculations of the structure are consistent with the experimental determination. The reactions of Ru(PP)(2)H-2 with diphenylgermane yield cis-[Ru(PP)(2)(GePh2H)H] exclusively for PP = dmpe and depe, while the cis isomer is dominant in the case of dppe. A photochemical competition reaction between Ru(dppe)(2)(H)(2) and the two substrates Ph2SiH2 and Ph2GeH2 results in both Si- H and Ge-H oxidative addition activation with a kinetic preference (0.18:1) for the germyl hydride product. Thermal conversion of Ru(dppe)(2)(SiPh2H)H to Ru(dppe)(2)(GePh2H)H is observed on heating.