Strong-Field Ionization and Coulomb Explosion of Chlorine Weakly Bound to Small Water Clusters

ROSS M. W., Berkdemir C., CASTLEMAN A. W.

JOURNAL OF PHYSICAL CHEMISTRY A, vol.116, no.33, pp.8530-8538, 2012 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 116 Issue: 33
  • Publication Date: 2012
  • Doi Number: 10.1021/jp3036617
  • Journal Name: JOURNAL OF PHYSICAL CHEMISTRY A
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.8530-8538
  • Erciyes University Affiliated: No

Abstract

Clusters exhibit an enhancement in ionization rates under intense, ultrafast laser pulses compared to their molecular/atomic counterparts Studies of ionization enhancement of weakly bound molecules to clusters have not been previously characterized and quantified. We demonstrate that weakly bound ClO to (H2O)(n) (n = 1-12) clusters and weakly bound HCl to (H2O)(n) (n = 1-12) clusters produce high atomic charge states of chlorine via Coulomb explosion. Density functional theory (DFT) was used to qualitatively compare the interaction energy of ClO with respect to the number of water molecules as well as HCl with respect to the number of water molecules. The chlorine ion signal intensity for each atomic charge state was observed to be dependent on the molecule-cluster bond strength. The observed ionization enhancement was quantified using semiclassical tunneling theory, and it was found that the Cl3+-5+ and O2+ charge states are enhanced in ionization. Possible mechanisms of ionization enhancement are explored for weakly bound chlorine species.