Phosphinodi(benzylsilane) PhP{(o-C6H4CH2)SiMe2H}2: A Versatile 鈥淧Si2Hx鈥?Pincer-Type Ligand at Ruthenium
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- 作者：Virginia Montiel-Palma ; Miguel A. Mu帽oz-Hern谩ndez ; Cynthia A. Cuevas-Ch谩vez ; Laure Vendier ; Mary Grellier ; Sylviane Sabo-Etienne
- 刊名：Inorganic Chemistry
- 出版年：2013
- 出版时间：September 3, 2013
- 年：2013
- 卷：52
- 期：17
- 页码：9798-9806
- 全文大小：394K
- 年卷期：v.52,no.17(September 3, 2013)
- ISSN：1520-510X
文摘
The synthesis of the new phosphinodi(benzylsilane) compound PhP{(o-C6H4CH2)SiMe2H}2 (1) is achieved in a one-pot reaction from the corresponding phenylbis(o-tolylphosphine). Compound 1 acts as a pincer-type ligand capable of adopting different coordination modes at Ru through different extents of Si鈥揌 bond activation as demonstrated by a combination of X-ray diffraction analysis, density functional theory calculations, and multinuclear NMR spectroscopy. Reaction of 1 with RuH2(H2)2(PCy3)2 (2) yields quantitatively [RuH2{[畏2-(HSiMe2)-CH2-o-C6H4]2PPh}(PCy3)] (3), a complex stabilized by two rare high order 蔚-agostic Si鈥揌 bonds and involved in terminal hydride/畏2-Si鈥揌 exchange processes. A small free energy of reaction (螖rG298 = +16.9 kJ mol鈥?) was computed for dihydrogen loss from 3 with concomitant formation of the 16-electron species [RuH{[畏2-(HSiMe2)-CH2-o-C6H4]PPh[CH2-o-C6H4SiMe2]}(PCy3)] (4). Complex 4 features an unprecedented 29Si NMR decoalescence process. The dehydrogenation process is fully reversible under standard conditions (1 bar, 298 K).