Gas-phase chemistry of Mo, Ru, W, and Os metal carbonyl complexes
Gas-phase chemistry of Mo, Ru, W, and Os metal carbonyl complexes
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Mo、Ru、W 和 Os 金属羰基配合物的气相化学
DOI：
10.1515/ract-2014-2157
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发表时间：
2014-02
影响因子：
1.8
通讯作者：
Gaeggeler, H. W.
中科院分区：
文献类型：
--
作者：
Li, Z.;Tan, C. -M.;Guo, J. -S.;Gaeggeler, H. W.
摘要采用金属羰基配合物，用在线低温等温气相色谱仪研究了Mo、Ru、W和Os同位素的气相化学行为。短寿命的Mo和Ru同位素是由252 Cf自发裂变源产生的。短寿命核素W和Os分别由重离子反应19 F +159 Tb和165 Ho产生。短寿命的产物在充满氦气和一氧化碳混合气体的反冲室中热化。然后将形成的羰基化合物通过毛细管输送到等温色谱柱，用于研究作为温度的函数的吸附行为。聚四氟乙烯（PTFE）和石英表面的在线等温色谱（IC）实验表明，所列元素的短寿命同位素可以形成非常挥发性的羰基络合物，最有可能在物理吸附过程中相互作用。Mo和Ru羰基化合物的推导吸附能分别为− 38 ± 2 kJ/mol和− 36 ± 2 kJ/mol。这些值与文献数据吻合良好，部分是用不同的色谱技术获得的。应用Monte Carlo模型对不同半衰期Mo同位素的吸附行为进行了验证，证明了该吸附模型的有效性。在没有任何预分离器的情况下，使用与重离子加速器耦合的气体喷射系统进行的调查清楚地表明了该方法的局限性。He和CO的混合气体直接加入到气室中，将导致CO气体分解并产生一些气溶胶颗粒。重离子实验中173 W和179 Os的实验后，Teflon柱被黄色的存款覆盖，因此不能正确地使用Monte Carlo模拟推导出W和Os羰基的吸附焓。
Abstract Metal carbonyl complexes were used for studying the gas-phase chemical behavior of Mo, Ru, W and Os isotopes with an on-line low temperature isothermal gas chromatography apparatus. Short-lived Mo and Ru isotopes were produced by a 252Cf spontaneous fission source. Short-lived nuclides of W and Os were produced using the heavy ion reactions 19F +159Tb and 165Ho, respectively. Short-lived products were thermalized in a recoil chamber filled with a gas mixture of helium and carbon monoxide. The carbonyls formed were then transported through capillaries to an isothermal chromatography column for study of the adsorption behavior as a function of temperature. On-line isothermal chromatography (IC) experiments on Teflon (PTFE) and quartz surfaces showed that short-lived isotopes of the listed elements can form carbonyl complexes which are very volatile and interact most likely in physical sorption processes. Deduced adsorption enthalpies of Mo and Ru carbonyls were − 38 ± 2 kJ/mol and − 36 ± 2 kJ/mol, respectively. These values are in good agreement with literature data, partly obtained with different chromatographic techniques. A validation of the applied Monte Carlo model to deduce adsorption enthalpies with Mo isotopes of different half-lives proved the validity of the underlying adsorption model. The investigations using a gas-jet system coupled to a heavy ion accelerator without any preseparator clearly showed the limitations of the approach. The He and CO gas mixture, which was directly added into the chamber, will result in decomposition of CO gas and produce some aerosol particles. After the experiment of 173W and 179Os in the heavy ion experiments, the Teflon column was covered by a yellowish deposit; the adsorption enthalpy of W and Os carbonyls could therefore not be properly deduced using Monte Carlo simulations.