title: Electric dipole moments of nanosolvated acid molecules in water clusters.
abstract: The electric dipole moments of (H2O)nDCl (n=3-9) clusters have been measured by the beam-deflection method. Reflecting the (dynamical) charge distribution within the system, the dipole moment contributes information about the microscopic structure of nanoscale solvation. The addition of a DCl molecule to a water cluster results in a strongly enhanced susceptibility. There is evidence for a noticeable rise in the dipole moment occurring at n≈5-6. This size is consistent with predictions for the onset of ionic dissociation. Additionally, a molecular-dynamics model suggests that even with a nominally bound impurity an enhanced dipole moment can arise due to the thermal and zero-point motion of the proton and the water molecules. The experimental measurements and the calculations draw attention to the importance of fluctuations in defining the polarity of water-based nanoclusters and generally to the essential role played by motional effects in determining the response of fluxional nanoscale systems under realistic conditions.
authors: Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA.
authors: Nicholas
authors: N
authors: Guggemos
authors: Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague, Czech Republic.
authors: Petr
authors: P
authors: Slavíček
authors: Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA.
authors: Vitaly V
authors: VV
authors: Kresin