单氢钌配合物与水和2,2,2-三氟乙醇的作用机理

Interaction Mechanisms of Ruthenium Hydride Complex with Water and 2,2,2-Trifluoroethanol

利用原位1H和31PNMR对单氢钌配合物TpRu(PPh3)(CH3CN)H[Tp=hydrotris(pyrazolyl)borate]与H2O和酸性HOCH2CF3的反应进行了研究,结果显示相应的反应产物分别是TpRu(PPh3)(CH3CN)(OH)和TpRu(PPh3)(CH3CN)(OCH2CF3).观察到反应过程中Ru—H…HOH和Ru—H…HOCH2CF3分子间的氢键作用.提出了生成TpRu(PPh3)(CH3CN)(OH)和TpRu(PPh3)(CH3CN)(OCH2CF3)的不同作用机理.在水存在下,TpRu(PPh3)(CH3CN)H与H2O反应,经过中间体TpRu(PPh3)(H2O)H和TpRu(PPh3)(OH)(η2-H2)生成产物TpRu(PPh3)(CH3CN)(OH).而TpRu(PPh3)(CH3CN)H与酸性HOCH2CF3反应时,单氢配体被质子化形成中间体[TpRu(PPh3)(CH3CN)-(η2-H2)](OCH2CF3),进而转变成产物TpRu(PPh3)(CH3CN)(OCH2CF3).TpRu(PPh3)(CH3CN)(OCH2CF3)与H2作用,经中间体TpRu(PPh3)(HOCH2CF3)H生成TpRu(PPh3)(η2-H2)H.

In situ ^1H and ^31p NMR methods were used to study the reactions of ruthenium hydride complex TpRu（PPh3）（CH3CN）H [Tp=hydrotris（pyrazolyl）borate] with water and acidic HOCH2CF3. The result shows that the the products were TpRu（PPh3）（CH3CN）（OH） and TpRu（PPh3）（CH3CN）（OCH/CF3）, respectively. The presence of Ru--H…HOH and Ru--H…HOCH/CF3 dihydrogen-bonding interactions was observed. The different mechanisms involving the formation of TpRu（PPh3）（CH3CN）（OH） and TpRu（PPh3）（CH3CN）（OCH/CF3） are proposed. In the presence of water, TpRu（PPh3）（CH3CN）H reacts with H/O to produce TpRu（PPh3）（CH3CN）（OH） via the intermediates TpRu（PPh3）（H/O）H and TpRu（PPh3）（OH）（η^2-H/）. However, in the case of CF3CH/OH, the protonation of the hydride ligand by CF3CH/OH generates a key species [TpRu（PPh3）（CH3CN）（η^2-H2）]（OCH2CF3）, which is then transformed to TpRu（PPh3）（CH3CN）（OCH/CF3）. TpRu（PPh3）（CH3CN）（OCH/CF3） reacts with H2 to result in the formation of TpRu（PPh3）（η^2-H/）H via the intermediate TpRu（PPh3）（HOCH/CF3）H.