Ultrafast Electron Crystallography:The Dawn of a New Era

摘要

In 1991,Williamson and Zewail took femtochemistry into the realm of diffraction,in particular into ultrafast electron diffraction (UED).The merit in doing so centered largely on the fact that electron diffraction entails the scattering of electrons off all the atoms and atom-atom pairs in the molecular assembly under investigation,in contrast to spectroscopy in which the probe is tuned to specific transitions in the molecule.In other words,an electron beam is sensitive to all species in its path and is hence potentially capable of uncovering the entire landscape of individual structures to which spectroscopy may be blind.