Electronic Fingerprint of the Protonated Imidazole Dimer Probed by X-ray Absorption Spectroscopy.
J Phys Chem Lett
; 15(5): 1264-1272, 2024 Feb 08.
Article
en En
| MEDLINE
| ID: mdl-38278137
ABSTRACT
Protons in low-barrier superstrong hydrogen bonds are typically delocalized between two electronegative atoms. Conventional methods to characterize such superstrong hydrogen bonds are vibrational spectroscopy and diffraction techniques. We introduce soft X-ray spectroscopy to uncover the electronic fingerprints for proton sharing in the protonated imidazole dimer, a prototypical building block enabling effective proton transport in biology and high-temperature fuel cells. Using nitrogen core excitations as a sensitive probe for the protonation status, we identify the X-ray signature of a shared proton in the solvated imidazole dimer in a combined experimental and theoretical approach. The degree of proton sharing is examined as a function of structural variations that modify the shape of the low-barrier potential in the superstrong hydrogen bond. We conclude by showing how the sensitivity to the quantum distribution of proton motion in the double-well potential is reflected in the spectral signature of the shared proton.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
J Phys Chem Lett
Año:
2024
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Article
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Suecia