Laboratorium für Physikalische Chemie, ETH Zürich, CH-8092 Zürich, Switzerland.
J Phys Chem A. 2010 Oct 28;114(42):11085-90. doi: 10.1021/jp101929d.
The pulsed-field-ionization zero-kinetic-energy photoelectron spectra of the origin band of the + 2A′′ ← 1A′ transition of propene (C3H6) and perdeuterated propene (C3D6) have been recorded at high resolution, allowing for the partial resolution of the rotational structure. The analysis of the spectra in the realm of the orbital ionization model for rigid-rotor asymmetric-top molecules enabled the determination of the adiabatic ionization energy of propene and the rotational constants of C3H6+ and C3D6+. The tunneling splittings resulting from the hindered rotation of the methyl group could not be resolved, and the analysis was therefore carried out in the Cs molecular symmetry group. Angular momentum contributions of pπ, dπ, and dδ character were included in the single-center expansion describing the molecular orbital out of which ionization occurs, leading to the selection rules |ΔN| = |N+ − N′′| ≤ 2 and ΔKa = Ka+ − Ka′′ = ±1, ±2 and to photoelectron partial waves with angular momentum quantum number up to l = 3. The observation of a strong spectral feature associated with ΔKa = 0 indicates the importance of vibronic interactions.
已在高分辨率下记录了丙烯（C3H6）和氘代丙烯（C3D6）的+2A′′ ← 1A′跃迁的起源带的脉冲场离子化零动能光电子能谱，从而部分解析了转动结构。在刚性转子非对称陀螺分子的轨道电离模型范围内对光谱进行分析，确定了丙烯的绝热电离能以及 C3H6+和 C3D6+的转动常数。由于甲基的受阻旋转而导致的隧道分裂无法分辨，因此在 Cs 分子对称群中进行了分析。在描述发生电离的分子轨道的单中心展开中，包含了 pπ、dπ 和 dδ 特征的角动量贡献，导致选择定则 |ΔN| = |N+ − N′′| ≤ 2 和 ΔKa = Ka+ − Ka′′ = ±1、±2，以及角动量量子数高达 l = 3 的光电子分波。观察到与 ΔKa = 0 相关的强谱特征表明了振动态相互作用的重要性。
