The vibronic structure of the first electronically excited state S1 and ionic ground state D0 of phenetole has been investigated by means of resonance enhanced multi photon ionization (REMPI) and mass analyzed threshold ionization (MATI) spectroscopy. The vibronic levels were assigned with the aid of quantum chemical calculations at the (TD)DFT level of theory and a multidimensional Franck-Condon approach. The S1 excitation energy of phenetole has been determined to be 36370 ± 4 cm−1 (4.5093 ± 0.0005 eV). The adiabatic ionization energy was determined to be 65665 ± 7 cm−1 (8.1415 ± 0.0008 eV). The vibronic structure has been analyzed whereby the in-plane bending vibration νbend shows high activity in the first excited state but is more pronounced in the ionic ground state. Moreover, a strong Duschinsky rotation effect can be observed for several D0←S1 transitions that causes violations of the Δv = 0 propensity rule.

中文翻译：

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苯乙醚第一激发态和离子基态的振动结构的详细分析

通过共振增强多光子电离（REMPI）和质量分析阈值电离（MATI）光谱研究了苯乙醚的第一电子激发态S1和离子基态D0的振动结构。借助 (TD)DFT 理论水平的量子化学计算和多维 Franck-Condon 方法分配振动能级。phenetole 的 S1 激发能量已确定为 36370 ± 4 cm-1 (4.5093 ± 0.0005 eV)。绝热电离能被确定为 65665 ± 7 cm-1 (8.1415 ± 0.0008 eV)。已经分析了振动结构，其中面内弯曲振动 νbend 在第一激发态显示出高活性，但在离子基态中更为明显。而且，