Isotope exchange and structural rearrangements in reactions between size-selected ionic water clusters, H3O(+)(H2O)(n) and NH4(+)(H2O)(n), and D2O |
| |
Authors: | Andersson Patrik Urban Ryding Mauritz Johan Sekiguchi Osamu Uggerud Einar |
| |
Institution: | Department of Chemistry, Atmospheric Science, G?teborg University, SE-412 96 G?teborg, Sweden. pan@chem.gu.se. |
| |
Abstract: | Hydrogen/deuterium exchange in reactions of H3O(+)(H2O)n and NH4(+)(H2O)n (1 < or = n < or = 30) with D2O has been studied experimentally at center-of-mass collisions energies of < or = 0.2 eV. For a given cluster size, the cross-sections for H3O(+)(H2O)n and NH4(+)(H2O)n are similar, indicating a structural resemblance and energetics of binding. For protonated pure water clusters, H3O(+)(H2O)n, reacting with D2O the main H/D exchange mechanism is found to be proton catalyzed. In addition the H/D scrambling becomes close to statistically randomized for the larger clusters. For NH4(+)(H2O)n clusters reacting with D2O, the main mechanism is a D2O/H2O swap reaction. The lifetimes of H3O(+)(H2O)n clusters have been estimated using RRKM theory and a plateau in lifetime vs. cluster size is found already at n = 10. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|