Fluctuating liquid structure induces ultrabroad infrared absorption—the hydrated proton on ultrafast time scales
Tuesday, July 5, 2016 - 09:01
in Physics & Chemistry
The elusive infrared absorption continuum of protons in aqueous environment has been topic of intense controversial debate since half a century. A team of scientists from the Max Born Institute and the Ben Gurion University of the Negev, Israel, show for the case of the Zundel cation (H₂O...H⁺...OH₂) H₅O₂⁺ that the surrounding liquid induces fluctuating electrical forces onto the proton, modulating its vibrational motions between the two water molecules. This mechanism, together with low-frequency thermal motions, results in the extreme broadening of the infrared spectrum.