Abstract
Competitive ion-dipole, ion-water, and water-water interactions were investigated at the molecular level in M +(CH 3CN) n(H 2O) m cluster ions for M = Na and K. Different [n,m] combinations for two different n + m cluster sizes were characterized with infrared predissociation spectroscopy in the O-H stretch region and MP2 calculations. In all cases, no differences were observed between the two alkali metal ions. The results showed that at the n + m = 4 cluster size, the solvent molecules interact only with the ion, and that the interaction between the ion and the large dipole moment of CH 3CN decreases the ion-water electrostatic interactions. At the n + m = 5 cluster size, at least two different hydrogen-bonded structures were identified. In these structures, the ion-dipole interaction weakens the ability of the ion to polarize the hydrogen bonds and thus decreases the strength of the water-water interactions in the immediate vicinity of the alkali metal ion.
Original language | English (US) |
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Pages (from-to) | 3880-3886 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry A |
Volume | 109 |
Issue number | 17 |
DOIs | |
State | Published - May 5 2005 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry