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分别研究了在干燥THF及H2O/THF条件下CO2与TpRu(PPh3)(CH3CN)H(Tp=Hy-drotris(pyrazolyl)borate)的反应,发现水对CO2插入TpRu(PPh3)(CH3CN)H的反应具有显著促进作用.原位高压NMR研究显示,在水存在下,CO2插入Ru-H键形成水合甲酸根配合物TpRu(PPh3)(CH3CN)(η1-OCHO)·H2O,其中甲酸根配体与溶剂中水分子形成分子间氢键.B3LYP水平的理论计算表明,CO2插入TpRu(PPh3)(CH3CN)H中Ru-H键的能垒由于水的存在而显著降低;在过渡态,CO2分子中碳原子的亲电性由于其氧原子与水分子形成氢键而得到增强.TpRu(PPh3)(CH3CN)(η1-OCHO)·H2O很快转化为另一甲酸根配合物TpRu(PPh3)(H2O)(η1-OCHO),并与之达成平衡.后者由于甲酸根配体与水分子配体间形成分子内氢键而稳定.
The reaction of CO2 with TpRu (PPh3) (CH3CN) H (Tp = Hy-drotris (pyrazolyl) borate) under dry THF and H2O / THF conditions was studied and it was found that water intercalates CO2 into TpRu (PPh3) The results of in situ high pressure NMR showed that CO2 intercalated with Ru-H bond in the presence of water to form the hydrate formate complex TpRu (PPh3) (CH3CN) (η1-OCHO) · H2O, in which the formate ligand And intermolecular hydrogen bonds with water molecules in the solvent.The theoretical calculations of B3LYP levels show that the energy barrier of Ru-H bonds in CO2 intercalated into TpRu (PPh3) (CH3CN) H is significantly reduced due to the presence of water; in the transition state, CO2 molecules The electrophilicity of the carbon atoms is enhanced by the formation of hydrogen bonds between their oxygen atoms and water molecules.TpRu (PPh3) (CH3CN) (η1-OCHO) · H2O is quickly converted to the other formate complex TpRu (PPh3) ( H2O) (η1-OCHO) which is in equilibrium with the latter due to the formation of intramolecular hydrogen bonds between the formate ligand and the water molecule ligand.