Interpretation of the X-Ray Emission Spectra of Liquid Water through Temperature and Isotope Dependence

Attosecond-pump attosecond-probe x-ray spectroscopy of liquid water

“…Notably, by performing the measurement before protons had time to move, we found experimental evidence that what is seen in x-ray emission spectroscopy (XES) as an outer-valence (1b 1 ) double-peak structure (32,33) is a consequence of proton motion in inner-shell-excited states; only a single peak was seen when proton motion was suppressed. This observation does not support the idea that the 1b 1 double-peak structure signals the presence of two competing structural motifs in liquid water at room temperature and addresses the long-standing debate surrounding the interpretation of XES in liquid water (32)(33)(34)(35)(36)(37). These two structural motifs have been suggested to exist at ambient conditions (24) as a persistence of the two phases of supercooled liquid water in "no man's land" (38)(39)(40)(41)(42).…”

Hydrogen-Bonded Structures of Water Molecules in Hydroxy-Functionalized Nanochannels of Columnar Liquid Crystalline Nanostructured Membranes Studied by Soft X-ray Emission Spectroscopy

“…The construction of new science focusing on the correlation between the structures of water molecules and the function of materials is attracting increasing attention. 19,53,54 The findings in this study provide new insight in terms of the correlation between the water transport mechanism and local structure of water molecules in the selforganized LC nanochannels.…”

“…This observation indicates that the ability of hydroxy groups to both donate and accept hydrogen bonds has no significant effect on the hydrogen-bonded structure of water molecules that do not directly interact with diol molecules. The construction of new science focusing on the correlation between the structures of water molecules and the function of materials is attracting increasing attention. ,, The findings in this study provide new insight in terms of the correlation between the water transport mechanism and local structure of water molecules in the self-organized LC nanochannels.…”

“…The peak 1b 1 ′ is enhanced for water molecules forming tetrahedrally coordinated hydrogen-bonded structures. The peak 1b 1 ″ arises dominantly from water molecules with highly distorted hydrogen bonding . The peak 3a 1 of liquid water is significantly reduced in comparison to the water molecule.…”

Temperature Dependence of Hydrogen Bond Networks of Liquid Water: Thermodynamic Properties and Structural Heterogeneity from Topological Descriptors

“…Several investigations employing experimental and modeling/simulation techniques point to a two-state model to describe the structure of water, with different structural motifs and two heterogeneous local densities: a low-density liquid, characterized by a more open local HB structure, and a high-density liquid with a not fully developed tetrahedrally coordinated HB network. ,− It was considered an interchange between these two temperature-dependent classes of local structures, reinforcing its dynamical feature, in which the rearrangements occur via structural fluctuations on a timescale longer than the HB average lifetime. To explain this behavior, the theoretical approach most widely accepted is based on the liquid–liquid critical point hypothesis, ,,,,,− which considers the existence of two phases of liquid water, connected by a first-order transition, with a critical point located at the supercooled liquid region of the water phase diagram.…”