A MOLECULAR BEAM PHOTOIONIZATION MASS SPECTROMETRIC STUDY OF CR(CO)6, MO(CO)6, AND W(CO)6
A MOLECULAR BEAM PHOTOIONIZATION MASS SPECTROMETRIC STUDY OF CR(CO)6, MO(CO)6, AND W(CO)6
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CR(CO)6、MO(CO)6和W(CO)6的分子束光离子化质谱研究
DOI：
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发表时间：
1997
期刊：
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通讯作者：
C. Ng
中科院分区：
文献类型：
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作者：
Y. Chen;C. Liao;C. Ng
测定了M(CO)6、M=Cr、Mo和W对M(CO)n+ (n= 0-6)在650-1600 A光子能量范围内的光电离效率（PIE）光谱。基于M(CO)6的电离能和M(CO)n+ (n= 0-5)的外观能（ae），我们得到了CO - M(CO)n−1+ (n=1 - 6)的顺序键解离能（D0）的估计。本文得到的Cr(CO)6+体系的D0值与最近碰撞诱导解离和理论研究的D0值的比较表明，基于该PIE实验的CO - m (CO)n−1+ (n= 3-6)的D0值是可靠的。PIE结果揭示了各D0值的总体趋势：D0[CO - cr (CO)n−1+]<D0[CO - mo (CO)n−1+]<D0[CO - w (CO)n−1+]（n=3 ~ 6）。本文得到的M(CO)6+的首D0值与前人报道的M(CO)6的首D0值的比较，有力地支持了M(CO)6中的相对论效应的重要性，相对论效应使得M(CO)6中M对CO的π-背给率更高。
The photoionization efficiency (PIE) spectra for M(CO)n+ (n=0–6) from M(CO)6, M=Cr, Mo, and W, have been measured in the photon energy range of 650–1600 A. Based on the ionization energies for M(CO)6 and appearance energies (AEs) for M(CO)n+ (n=0–5) determined here, we have obtained estimates for the sequential bond dissociation energies (D0) for CO–M(CO)n−1+ (n=1–6). The comparison between the D0 values for the Cr(CO)6+ system obtained here and in the recent collisional induced dissociation and theoretical studies suggests that D0 values for CO–M(CO)n−1+ (n=3–6) based on this PIE experiment are reliable. The PIE results reveal the general trend for individual D0 values that D0[CO–Cr(CO)n−1+]<D0[CO–Mo(CO)n−1+]<D0[CO–W(CO)n−1+] (n=3–6). The comparison of the first D0 values for M(CO)6+ obtained here and those for M(CO)6 reported previously provides strong support for the theoretical analysis that the importance of relativistic effects, which give rise to more efficient M to CO π-back-donation in M(CO)6, is...