Water clusters embedding a nitric acid molecule HNO3(H2O)_{n=1-10} areinvestigated via electrostatic deflection of a molecular beam. We observe largeparaelectric susceptibilities that greatly exceed the electronicpolarizability, revealing the contribution of permanent dipole moments. Themoments derived from the data are also significantly higher than those of purewater clusters. An enhancement in the susceptibility for n=5,6 and a rise incluster abundances setting in at n=6 suggest that dissociation of the solvatedacid molecule into ions takes place in this size range.
展开▼
