Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, China.
J Phys Chem A. 2011 May 5;115(17):4248-54. doi: 10.1021/jp2000927. Epub 2011 Apr 1.
Negative ions Cl(-), Cl(2)(-), CCl(-), CHCl(-), and CCl(2)(-) are observed in vacuum-ultraviolet ion-pair photodissociations of chloroform (CCl(3)H) using the Hefei synchrotron radiation facility, and their ion production efficiency curves are recorded in the photon energy range of 10.00-21.50 eV. Two similar spectra of the isotope anions (35)Cl(-) and (37)Cl(-) indicate the following: Besides the strong bands corresponding to the electron transitions from valence to Rydberg orbitals converging to the ionic states, some additional peaks can be assigned with the energetically accessible multibody fragmentations; a distinct peak at photon energy 14.55 eV may be due to a cascade process (namely, the Cl(2) neutral fragment at the highly excited state D'2(3)Π(g) may be produced in the photodissociation of CCl(3)H, and then the Cl(-) anions are produced in the pulsed-field induced ion-pair dissociations of Cl(2) (D'2(3)Π(g))); two vibrational excitation progressions, nν(2)(+) and nν(2)(+) + ν(3)(+), and nν(4)(+) and nν(4)(+) + ν(2)(+), are observed around C̃ (2)E and D̃ (2)E ionic states, respectively. The enthalpies of the multibody fragmentations to Cl(2)(-), CCl(-), CHCl(-), and CCl(2)(-) are calculated with the thermochemistry data available in the literature, and these multibody ion-pair dissociation pathways are tentatively assigned in the respective anion production spectra.
在使用合肥同步辐射装置进行的氯仿（CCl3H）真空紫外光电离解离实验中，观察到了 Cl(-)、Cl2(-)、CCl(-)、CHCl(-)和 CCl2(-)等负离子，记录了它们在光子能量范围为 10.00-21.50 eV 的离子生成效率曲线。两种类似的同位素负离子（35）Cl(-)和（37）Cl(-)的光谱表明：除了对应于价电子向里德堡轨道跃迁并收敛到离子态的强带外，还可以用能量上可达到的多体碎片化来分配一些额外的峰；光子能量为 14.55 eV 的明显峰可能是由于级联过程（即，在 CCl3H 的光解过程中，可能在高度激发态 D'2(3)Π(g)中产生 Cl2 中性碎片，然后在脉冲场诱导的 Cl2(D'2(3)Π(g))离子对解离中产生 Cl(-)阴离子）；在 C̃(2)E 和 D̃(2)E 离子态附近观察到 nν(2)(+)和 nν(2)(+) + ν(3)(+)以及 nν(4)(+)和 nν(4)(+) + ν(2)(+)两个振动激发进展，这些进展分别与离子态相对应。利用文献中可用的热化学数据计算了 Cl2(-)、CCl(-)、CHCl(-)和 CCl2(-)的多体碎片化焓，并在各自的阴离子生成光谱中初步分配了这些多体离子对解离途径。
