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用原位红外光谱法研究了负载于MgO表面上的〔PPN〕_2〔Ru_3(CO)_9CCO〕簇合物。发现表面物类同MgO的抽空脱水温度有很大关系。在573K以下脱水的氧化镁上〔PPN〕_2〔Ru_3-(CO)_9CCO〕吸附后,其v_(?)=o的红外谱基本保持乙烯酮钌簇合物的原来特征,〔Ru_3(CO)_9-CCO〕~(2-)离子和表面的电荷相互作用只引起线式和桥式CO谱带的轻微位移。抽空脱水温度超过613K时,除了〔Ru_3(CO)_9CCO〕~(2-)的特征光谱外,还出现2068,2030和1999cm~(-1)新谱带,归因于Mg-OH同〔Ru_3(CO)_9CCO〕~(2-)反应部分地形成〔HRu_3(CO)_9CCO〕~-.TPD-IR研究揭示了〔Ru_3(CO)_9CCO〕~(2-)/MgO的热稳定性远大于〔PPN〕_2〔Ru_3(CO)_9CCO〕固体。在CO气氛下,〔Ru_3(CO)_9CCO〕~(2-)同CH_3I很易反应,v_(?)=o谱带的变化说明反应后有乙酰基生成,v_(?)=o谱带出现在1635cm~(-1)。这种含乙酰基的三钌化合物〔Ru_3(CO)_9CC(O)CH_3〕~-对CO+H_2合成C_2含氧物的机理研究,可能有模型化合物的意义。
The [PPN] _2 [Ru_3 (CO) _9CCO] clusters supported on the surface of MgO were investigated by in situ FTIR spectroscopy. It is found that there is a great relationship between the surface species and the evacuation dehydration temperature of MgO. The infrared spectra of v_ (?) = O after the adsorption of [PPN] _2 [Ru_3- (CO) _9CCO] on magnesium oxide dehydrated below 573K kept the original features of the ruthenium- _9-CCO] ~ (2-) ions and the surface charges only cause slight shifts of the linear and the bridged CO bands. In addition to the characteristic spectra of [Ru_3 (CO) _9CCO] ~ (2-), the new bands of 2068, 2030 and 1999cm -1 also appear due to dehydration temperature of more than 613K, which is attributed to the fact that Mg- (CO) _9CCO] ~ (2-) reaction partially formed 〔HRu_3 (CO) _9CCO〕 ~ -TPD-IR study revealed that the thermal stability of [Ru_3 (CO) _9CCO] ~ (2 -) / MgO was far greater than [PPN] _2 [Ru_3 (CO) _9CCO] solid. The reaction of [Ru_3 (CO) _9CCO] ~ (2-) with CH_3I is easy to react under CO atmosphere. The change of v_ (?) = O band indicates that acetyl group is formed after the reaction, v_ Now 1635cm ~ (-1). The mechanism of synthesizing C_2 oxygenates from CO + H_2 by this kind of acetyl-containing tri-ruthenium compound [Ru_3 (CO) _9CC (O) CH_3] ~ may have the significance of model compounds.