Making the molecular movie with atomic-scale spatial resolution and femtosecond/attosecond-scale time resolution

我们建议利用两种新的超短XUV或X射线源，即高次谐波产生（HHG）和自由电子激光器（FEL），开发和执行旨在检索经历动力学的分子的电子结构和随时间变化的空间构型的实验。我们的目标是利用通过光电离发射的电子以前所未有的精度获得有关电子和分子结构的信息。当动能较高时（型）。100到300电子伏特)离开分子内的一个位置，它可能会散射掉另一个原子核或干扰从分子中等效位置发射的电子。因此，光电子的角度分布携带着有关单个原子核相对位置的信息。该实验将结合三项前沿技术，(i)超短飞秒和/或阿秒XUV光源，（ii）激光诱导分子定位（在空间中固定分子轴）和（iii）角度和动能分辨光电子能谱。我们计划研究CF3I的解离动力学，C2H4的异构化动力学，以及1,22二碘乙烷和4,4'二碘偶氮苯的异构体互连途径和动力学。电子构型和分子结构的时间演变将使用上述XUV或X射线光电离为基础的电子衍射测量来监测。因此，我们的目标是接近化学中的圣杯之一，即及时跟踪化学反应的所有方面。

We propose to develop and perform experiments aimed at retrieving the electronic structure and time dependent spatial configuration of molecules that undergo dynamics, making use of two newly available ultrashort XUV or X ray sources, namely high order harmonic generation (HHG) and free electron lasers (FEL). We aim to obtain information about the electronic and molecular structure with an unprecedented level of precision using electrons that are emitted through photoionization. When a high kinetic energy (typ. 100 to 300 eV) leaves a site within the molecule, it may scatter off one of the other nuclei or interfere with electrons emitted from equivalent sites in the molecule. Consequently the photoelectron angular distribution carries information about the relative position of the individual nuclei. The experiment will combine three forefront technologies, (i) ultrashort femtosecond and or attosecond XUV light sources, (ii) laser induced molecular alignment (to fix the molecular axis in space) and (iii) angle and kinetic energy resolved photoelectron spectroscopy. We plan to investigate the dissociation dynamics of CF3I, the isomerization dynamics of C2H4 and the isomer interconnection pathways and dynamics of 1,2diiodoethane and 4,4'diiodoazobenzene. Both the time evolution of the electronic configuration and the molecular structure will be monitored using the above mentioned XUV or X ray photoionization based electron diffraction measurements. We aim thereby to approach one of the Holy Grails in chemistry, i.e. to follow in time all aspects of a chemical reaction.