论文标题
气相分子的超快电子衍射成像
Ultrafast electron diffraction imaging of gas-phase molecules
论文作者
论文摘要
分子结构的知识对于理解和最终影响化学反应性至关重要。在近一个世纪以来，衍射成像一直用于识别许多与原子（即Angstrom，A; 1 a; 1 a = 10 $^{ - 10} $ M）空间分辨率的许多生物相关的气相分子的结构。阐明化学反应的机制需要能够记录分子结构的多个良好解决的快照，因为它正在核上发展（即fomtosecond，fs; 1 fs; 1 fs = 10 $^{ - 15} $ s）时间尺度。我们介绍了最新的最先进的超快电子衍射方法，该方法用于检索使用Angstrom和飞秒时空分辨率检索气相分子的分子结构。我们首先在其用于结构检索的应用中提供了弹性电子散射的历史和理论背景，然后提供无野外和野外超快电子衍射技术的细节。在提供未来的领域前景以及当今和将来存在的挑战之前，我们讨论了这些超快方法在实时延时化学反应中的应用。
Knowledge of molecular structure is paramount in understanding, and ultimately influencing, chemical reactivity. For nearly a century, diffractive imaging has been used to identify the structures of many biologically-relevant gas-phase molecules with atomic (i.e. Angstrom, A; 1 A = 10$^{-10}$ m) spatial resolution. Unravelling the mechanisms of chemical reactions requires the capability to record multiple well-resolved snapshots of the molecular structure as it is evolving on the nuclear (i.e. femtosecond, fs; 1 fs = 10$^{-15}$ s) timescale. We present the latest, state-of-the-art ultrafast electron diffraction methods used to retrieve the molecular structure of gas-phase molecules with Angstrom and femtosecond spatio-temporal resolution. We first provide a historical and theoretical background to elastic electron scattering in its application to structural retrieval, followed by details of field-free and field-dressed ultrafast electron diffraction techniques. We discuss the application of these ultrafast methods to time-resolving chemical reactions in real-time, before providing a future outlook of the field and the challenges that exist today and in the future.
