Photodissociation spectroscopy of the chromium trimer ion
Photodissociation spectroscopy of the chromium trimer ion
复制标题
三聚铬离子的光解光谱
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
T. Kondow
中科院分区：
文献类型：
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作者：
T. Majima;K. Tono;A. Terasaki;Y. Kawazoe;T. Kondow
抽象的。用光解光谱研究了三聚铬离子Cr3+在1.32~5.52 eV光子能量范围内的电子结构、几何结构和光解动力学。
产物离子Cr~+和Cr~（2+）的分支分数在分解为Cr~（++）Cr~（2+）、Cr~（++）Cr~（2+）、Cr~（++）Cr~（2+）和Cr~（++）Cr~（2+）的阈值能量处呈现阶梯式变化。
值得注意的是，甚至在原子化阈值以上产生Cr2 +;多余的能量被重新分配以产生处于激发态的碎片原子Cr *。
通过密度泛函计算确定的两种近简并结构异构体的模拟光谱的混合物很好地解释了光解离作用光谱：
具有亚稳C2v结构和最稳定结构的那些从C2v结构稍微变形。
两种异构体之间的势垒高度低于零点能，表明Cr 3+具有内在的松软结构。
Abstract. The electronic and geometric structures and photodissociation dynamics of the chromium trimer ion, Cr3+, were investigated by photodissociation spectroscopy in the photon-energy range from 1.32 to 5.52 eV.
The branching fractions of the product ions, Cr+ and Cr2+, exhibit stepwise changes at the threshold energies for dissociation into Cr++Cr2, Cr+Cr2+, Cr++2Cr, and Cr*+Cr2+.
It is noted that Cr2+ is produced even above the threshold for atomization; the excess energy is redistributed to produce a fragment atom, Cr*, in an excited state.
The photodissociation action spectrum is well explained by a mixture of simulated spectra for two nearly-degenerate structural isomers identified by density functional calculations:
those having a metastable C2v structure and the most stable structure slightly distorted from the C2v one.
The barrier height between the two isomers which is lower than the zero-point energy suggests that Cr3+ has an intrinsically floppy structure.