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DOE OSTI · 1756131

Crossover from hydrogen to chemical bonding

Dereka, Bogdan·Yu, Qi·Lewis, Nicholas H. C.·Carpenter, William B.·Bowman, Joel M.·Tokmakoff, Andrei
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Abstract

Hydrogen bonds (H-bonds) can be interpreted as a classical electrostatic interaction or as a covalent chemical bond if the interaction is strong enough. As a result, short strong H-bonds exist at an intersection between qualitatively different bonding descriptions, with few experimental methods to understand this dichotomy. The [F-H-F] − ion represents a bare short H-bond, whose distinctive vibrational potential in water is revealed with femtosecond two-dimensional infrared spectroscopy. It shows the superharmonic behavior of the proton motion, which is strongly coupled to the donor-acceptor stretching and disappears on H-bond bending. In combination with high-level quantum-chemical calculations, we demonstrate a distinct crossover in spectroscopic properties from conventional to short strong H-bonds, which identify where hydrogen bonding ends and chemical bonding begins.

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Dereka, Bogdan, Yu, Qi, Lewis, Nicholas H. C., Carpenter, William B., Bowman, Joel M., Tokmakoff, Andrei. 2021-01-07. Crossover from hydrogen to chemical bonding. https://doi.org/10.1126/science.abe1951

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