ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.
Department of Chemistry, University of Warsaw, 02-093 Warsaw, Poland.
Proc Natl Acad Sci U S A. 2019 Apr 23;116(17):8173-8177. doi: 10.1073/pnas.1817465116. Epub 2019 Apr 5.
Structural information on electronically excited neutral molecules can be indirectly retrieved, largely through pump-probe and rotational spectroscopy measurements with the aid of calculations. Here, we demonstrate the direct structural retrieval of neutral carbonyl disulfide (CS) in the [Formula: see text] excited electronic state using laser-induced electron diffraction (LIED). We unambiguously identify the ultrafast symmetric stretching and bending of the field-dressed neutral CS molecule with combined picometer and attosecond resolution using intrapulse pump-probe excitation and measurement. We invoke the Renner-Teller effect to populate the [Formula: see text] excited state in neutral CS, leading to bending and stretching of the molecule. Our results demonstrate the sensitivity of LIED in retrieving the geometric structure of CS, which is known to appear as a two-center scatterer.
可以通过泵浦探测和旋转光谱测量，并借助计算，间接地获取处于电子激发态的中性分子的结构信息。在此，我们利用激光诱导电子衍射（LIED）直接获取 [Formula: see text] 电子激发态下中性二硫化碳（CS）的结构信息。我们采用皮米和阿托秒分辨率的脉冲内泵浦探测技术，明确识别出经场修饰的中性 CS 分子超快对称伸缩和弯曲振动。我们利用 Renner-Teller 效应将中性 CS 分子激发到 [Formula: see text] 激发态，导致分子弯曲和伸缩。实验结果表明，LIED 在获取 CS 几何结构方面具有较高的灵敏度，CS 已知表现为双中心散射体。
