Vacuum ultraviolet photoionization mass spectrometric study of C60
Vacuum ultraviolet photoionization mass spectrometric study of C60
复制标题
C60的真空紫外光电离质谱研究
DOI：
10.1063/1.462112
复制
发表时间：
1992
影响因子：
4.4
通讯作者：
J. Berkowitz
中科院分区：
文献类型：
--
作者：
R. M. Yoo;B. Ruscic;J. Berkowitz
在电离阈值和40.8 eV之间，用光电离质谱法研究了气态C60。观察到的绝热阈值为7.57±0.01 eV，由于热带的存在，该阈值可能略低。光离子产率曲线的能量导数在某些峰的位置与He i光电子能谱大致一致，但其他峰较弱或不存在。这种差异不是由自电离引起的，而是由控制低能电子向高角动量波抛射的选择规则引起的。在更高的能量下观察到C+60，在40.8 eV时强度为C+60的约0.6。c++ 60的光离子产率曲线在远高于阈值的地方近似为线性，在阈值附近表现出曲率，这阻碍了区分第二电离势的两个可选值的尝试。只有在最高能量（40.8 eV）时才能观察到分裂形成C+58。准平衡理论模拟了单分子衰变。在这个模型中，…
Gaseous C60 has been studied by photoionization mass spectrometry between the ionization threshold and 40.8 eV. An adiabatic threshold of 7.57±0.01 eV is observed, which may be slightly low due to hot bands. The energy derivative of the photoion yield curve is in rough agreement with the He i photoelectron spectrum on the positions of some peaks, but others are weak or absent. The discrepancy is not attributed to autoionization, but rather to selection rules governing the ejection of low energy electrons into high angular momentum waves. C++60 is observed at higher energies, and becomes ∼0.6 as intense as C+60 at 40.8 eV. The photoion yield curve of C++60, approximately linear well above threshold, appears to exhibit curvature near threshold, thwarting an attempt to make a distinction between two alternative values of the second ionization potential. Fragmentation to form C+58 is only observed at the highest energy, 40.8 eV. The unimolecular decay is modelled by quasiequilibrium theory. In this model, the...