The photoelectron spectrum (PES) of trans-1,2-C₂H₂Cl₂ has been measured with the resonance lines in He, Ne and Ar. These spectra are compared to the threshold photoelectron spectrum (TPES) recorded using synchrotron radiation. Nine mostly well separated photoelectron bands are observed at adiabatic ionization energies of 9.633 eV, 11.840 eV, 12.044 eV, 12.582 eV, 13.581 eV, 14.081 eV, 15.724 eV and at about 16.325 eV and 19.00 eV. Most of them exhibit a well resolved and extended vibrational structure. The He-I photoelectron band associated with the ground electronic state of the ion and the corresponding TPES band are characterized by a vibrational structure extending over 0.7 eV and 2.0 eV respectively. In the latter case the strong correlation between the TPES and the photoabsorption spectrum in the same energy region has been established. Several excited states also show an extended vibrational structure. The assignments of the electronic bands and of the vibrational wavenumbers were supported by quantum chemical calculations. The good correlation between predicted vibrational wavenumbers and the experimental values allowed us to assign most of the vibrational structures. The constant ion state (CIS) spectra have been recorded and discussed for selected vibrational levels of the ground state and for the adiabatic transition to the first excited state of the ion.

反式1,2-C ₂ H ₂ Cl ₂的光电子能谱（PES）用He，Ne和Ar中的共振线测量。将这些光谱与使用同步加速器辐射记录的阈值光电子光谱（TPES）进行比较。在绝热电离能为9.633 eV，11.840 eV，12.044 eV，12.582 eV，13.581 eV，14.081 eV，15.724 eV以及约16.325 eV和19.00 eV的条件下观察到九个大部分分离良好的光电子带。它们中的大多数表现出良好的分辨和扩展的振动结构。与离子的基态电子态相关的He-I光电子能带和相应的TPES能带的特征是振动结构分别超过0.7 eV和2.0 eV。在后一种情况下，已经建立了TPES与同一能量区域中的光吸收光谱之间的强相关性。几种激发态也显示出扩展的振动结构。电子带和振动波数的分配得到了量子化学计算的支持。预测的振动波数与实验值之间的良好相关性使我们可以分配大多数振动结构。已记录并讨论了恒定离子态（CIS）光谱，用于基态的选定振动能级和绝热过渡到离子的第一激发态。