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Revealing excess protons in the infrared spectrum of liquid water.

ABSTRACT: The most common species in liquid water, next to neutral [Formula: see text] molecules, are the [Formula: see text] and [Formula: see text] ions. In a dynamic picture, their exact concentrations depend on the time scale at which these are probed. Here, using a spectral-weight analysis, we experimentally resolve the fingerprints of the elusive fluctuations-born short-living [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] ions in the IR spectra of light ([Formula: see text]), heavy ([Formula: see text]), and semi-heavy (HDO) water. We find that short-living ions, with concentrations reaching [Formula: see text] of the content of water molecules, coexist with long-living pH-active ions on the picosecond timescale, thus making liquid water an effective ionic liquid in femtochemistry.

SUBMITTER: Artemov VG

PROVIDER: S-EPMC7347896 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

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Revealing excess protons in the infrared spectrum of liquid water.

Artemov Vasily G VG Uykur Ece E Roh Seulki S Pronin Artem V AV Ouerdane Henni H Dressel Martin M

Scientific reports 20200709 1

The most common species in liquid water, next to neutral [Formula: see text] molecules, are the [Formula: see text] and [Formula: see text] ions. In a dynamic picture, their exact concentrations depend on the time scale at which these are probed. Here, using a spectral-weight analysis, we experimentally resolve the fingerprints of the elusive fluctuations-born short-living [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] ions in the IR spectra of light ([For ...[more]

PMID: 32647228

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