Water's ability to form hydrogen bond networks underlies its unique properties. Microhydration, which is the binding of a few water molecules to solutes, can significantly alter both the hydrogen bond network compared to pure water and the solute's structure. Here, we highlight selected solute-water complexes that display notable internal dynamics and structural changes upon microhydration, studied using a tight combination of rotational spectroscopy and quantum-chemical calculations. We also demonstrate how nuclear quadrupole coupling effectively probes changes in the electronic environment during microhydration, offering insights into processes such as acid dissociation.
Loru et al. (Mon,) studied this question.