Ion‐pair formation from saturated hydrocarbons through photoexcitation of an inner‐valence electron
Ion‐pair formation from saturated hydrocarbons through photoexcitation of an inner‐valence electron
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通过内价电子的光激发从饱和烃形成离子对
DOI：
10.1063/1.465856
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发表时间：
1993
影响因子：
4.4
通讯作者：
H. Yoshida
中科院分区：
文献类型：
--
作者：
K. Mitsuke;H. Hattori;H. Yoshida
通过负离子质谱法使用同步辐射在15-35 eV光子能量范围内研究了饱和烃的超激发态的离子对形成。在CH 4、C2 H6、C3 H8、n-C4 H10、iso-C4 H10和neo-C5 H12中观察到负离子H−。最大横截面范围为1.6×10−21至1.0×10−20 cm 2。在H−的光解离效率曲线中观察到的强峰被认为是由碳2s-型分子轨道中的电子促进形成的里德堡态跃迁引起的。相比之下，从碳2 p-型轨道的价-里德堡跃迁对H−的形成几乎没有贡献（C2 H6）[CH 4和CmH 2 m +2（3≤m≤5）]。这种差异可以解释为，由于电子交换过程中涉及的两个碳2 p-型轨道之间相对较大的重叠，后者的里德伯态相对于自电离到较低离子态具有较短的寿命。
Ion‐pair formation from the superexcited states of saturated hydrocarbons has been studied by negative‐ion mass spectrometry using synchrotron radiation in the 15–35 eV photon energy range. Negative ion H− has been observed from CH4, C2H6, C3H8, n‐C4H10, iso‐C4H10, and neo‐C5H12. The maximum cross section ranges from 1.6×10−21 to 1.0×10−20 cm2. Strong peaks observed in the photodissociation efficiency curve of H− are assigned as resulting from transitions to the Rydberg states formed by promotion of an electron in a carbon 2s‐type molecular orbital. In contrast, the valence‐Rydberg transitions from a carbon 2p‐type orbital have little (C2H6) or no contribution [CH4 and CmH2m+2 (3≤m≤5)] to the H− formation. This difference can be interpreted as that the latter Rydberg states have short lifetime with respect to autoionization to lower ionic states on account of relatively large overlap between two carbon 2p‐type orbitals involved in an electron exchange process.
DOI：
10.1016/0368-2048(82)85046-9
发表时间：
1982
影响因子：
1.9
作者：
M. Robin
通讯作者：
M. Robin