Photoelectron spectroscopic correlation of the molecular orbitals of methane, ethane, propane, isobutane and neopentane
Photoelectron spectroscopic correlation of the molecular orbitals of methane, ethane, propane, isobutane and neopentane
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甲烷、乙烷、丙烷、异丁烷和新戊烷分子轨道的光电子能谱关联
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发表时间：
1972
期刊：
影响因子：
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通讯作者：
W. Schmidt
中科院分区：
文献类型：
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作者：
J. Murrell;W. Schmidt
通过He（I）PE光谱研究了CH_4-n（CH_3）_n系列的能级变化趋势，并用从头算SCF计算和“等效轨道”处理方法进行了讨论。在异丁烷和新戊烷的光谱中的第一个频带被分裂成两个和三个分量分别由Jahn-Teller力，这意味着这些频带来自主要位于CC键的MO。由此推导出丙烷（4 b1，CC）和乙烷（3a 1g，CC）中最高占据MO的对称性，在后一种情况下的分配不同于其他工作者。甲基的形式简并伪π CH轨道被“穿越空间”相互作用分裂，在新戊烷的情况下达到2.7 eV。早期试图解释线性和支链烷烃的PE光谱被认为是不充分的，因为后者的影响没有得到充分考虑。
Energy level trends across the series CH4–n(CH3)n have been studied by He(I) PE spectroscopy and are discussed in terms of ab-initio SCF calculations and an “equivalent orbital” treatment. The first band in the spectra of isobutane and neopentane is split by Jahn-Teller forces into two and three components respectively, implying that these bands originate from MOs localized mainly in the CC bonds. From this the symmetry of the highest occupied MO in propane (4b1, CC) and ethane (3a1g, CC) is deduced, an assignment which in the latter case differs from that of other workers. Formally degenerate pseudo-π CH orbitals of the methyl groups are split by “through space” interactions which amount to 2.7 eV in the case of neopentane. Earlier attempts to interpret the PE spectra of linear and branched alkanes are considered to be inadequate because this latter effect was not taken into full account.