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Updated: Jun 24, 2025

Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy
Published on: May 27, 2018
Electric nuclear quadrupole coupling reveals dissociation of HCl with a few water molecules
Fan Xie1, Denis S Tikhonov1, Melanie Schnell1,2
1Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany.
Abstract:
Investigating the dissociation of acids in the presence of a limited number of water molecules is crucial for understanding various elementary chemical processes. In our study, focusing on HCl(H2O) clusters (where HCl is hydrogen chloride and H2O is water) formed in a cold and isolated jet expansion, we used the nuclear quadrupole coupling tensor obtained through rotational spectroscopy to decipher the nature of the hydrogen-chlorine (H-Cl) chemical bond in a microaqueous environment. For n = 1 to 4, the H-Cl bond is covalent. At n = 5 and 7, the contact ion pair of H3O+Cl- is spontaneously formed within the hydrogen bond networks of book and cube acid-water clusters, respectively.
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