Polarization dependent photoelectron spectra encompassing the outer valence orbitals of oxalyl chloride have been recorded in the photon energy range 19 – 91 eV. These have allowed photoelectron anisotropy parameters and branching ratios to be determined. Photoionization partial cross sections and photoelectron anisotropy parameters have been calculated with the Continuum Multiple Scattering – Xα approach. Four of the outer valence orbitals are predicted to possess a significant Cl 3p lone-pair character and have closely grouped binding energies. The photoionization dynamics of these four orbitals are predicted to be strongly affected by the Cooper minimum associated with the Cl 3p orbital in the isolated atom at photon energies around 40 eV. A comparison between the theoretical and measured photoelectron anisotropy parameters has enabled the molecular orbital sequence to be clarified. A doublet has been observed in the region of the photoelectron spectrum where a band due to the 5b_u orbital might be anticipated. Our calculations indicate that the 6b_u and 5b_u orbitals are coupled. This coupling may account for the apparent lack of a pronounced Cooper minimum in the β-parameter associated with the nominal 6b_u ionization and for the unexpected appearance of the adjacent photoelectron band, nominally associated with the 5b_u orbital. The vertical ionization energy of the outermost 7a_g orbital was experimentally determined to be 11.266±0.005 eV.

在光子能量范围为19 – 91 eV的范围内，已记录了围绕草酸氯的外价轨道的与偏振有关的光电子光谱。这些使得可以确定光电子各向异性参数和分支比。光电离的局部截面和光电子各向异性参数已使用Continuum Multiple Scattering –Xα方法进行了计算。预测四个外价轨道具有明显的Cl 3 p孤对特征并具有紧密分组的结合能。预测这四个轨道的光电离动力学将受到与Cl 3 p相关的Cooper最小值的强烈影响。在40 eV附近的光子能量下，孤立原子的轨道。理论和测量的光电子各向异性参数之间的比较使分子轨道序列得以澄清。在光电子谱的区域中已经观察到双峰，其中可能预期到由于5 b _u轨道引起的能带。我们的计算表明6 b _u和5 b _u轨道是耦合的。这种耦合可以解释明显缺乏一个明显库珀最小的的β与标称6相关联-parameter b _ù电离和用于相邻光电子带的意想不到的外观，名义上与5相关联b_你的轨道。实验确定最外层7 a _g轨道的垂直电离能为11.266±0.005 eV。