How soft X-rays reveal the hydrogen bonds in liquid water

The application of soft X-ray techniques to the study of the hydrogen bonding network in liquid water has been reviewed by scientists in Germany. Although the existence of aqueous hydrogen bonds is well established, its exact structure is still a hot topic. Examining the electronic structure can tell us a lot about the molecular arrangment, which is where soft X-rays come in.

Techniques like X-ray absorption spectroscopy, X-ray photoelectron spectroscopy and X-ray emission spectroscopy were discussed in a focus review in Chemistry – An Asian Journal. The problems associated with the use of soft X-rays under vacuum conditions for studying liquids are described, with possible solutions, and the interpretation of the spectroscopic data is discussed.