Structural independence of hydrogen-bond symmetrisation dynamics at extreme pressure conditions

Titelangaben

Meier, Thomas ; Trybel, Florian ; Khandarkhaeva, Saiana ; Laniel, Dominique ; Ishii, Takayuki ; Aslandukova, Alena ; Dubrovinskaia, Natalia ; Dubrovinsky, Leonid:
Structural independence of hydrogen-bond symmetrisation dynamics at extreme pressure conditions.
In: Nature Communications. Bd. 13 (2022) Heft 1 . - 3042.
ISSN 2041-1723
DOI: https://doi.org/10.1038/s41467-022-30662-4

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Abstract

The experimental study of hydrogen-bonds and their symmetrization under extreme conditions is predominantly driven by diffraction methods, despite challenges of localising or probing the hydrogen subsystems directly. Until recently, H-bond symmetrization has been addressed in terms of either nuclear quantum effects, spin crossovers or direct structural transitions; often leading to contradictory interpretations when combined. Here, we present high-resolution in-situ 1H-NMR experiments in diamond anvil cells investigating a range of systems containing linear O-H ⋯  O units at pressure ranges of up to 90 GPa covering their respective H-bond symmetrization. We found pronounced minima in the pressure dependence of the NMR resonance line-widths associated with a maximum in hydrogen mobility, precursor to a localisation of hydrogen atoms. These minima, independent of the chemical environment of the O-H ⋯  O unit, can be found in a narrow range of oxygen oxygen distances between 2.44 and 2.45 Å, leading to an average critical oxygen-oxygen distance of r¯critOO=2.443(1) Å.