Protonated Water Clusters

Протонированные кластеры воды

Magic number (H₂O)₂₁+ cluster

Support National Science Foundation Department of Energy

Co-workers

R. A. Christie, J. Cui, E. M. Myshakin, T. H. Choi - Univ. Pittsburgh M. A. Johnson, J. -W. Shin, N. I. Hammer, E. G. Diken - Yale M. A. Duncan, R. S. Walters, T. D. Jaeger - Univ. of Georgia

Computational resources

• CMMS (Univ. of Pittsburgh) • Pittsburgh Supercomputing

Center • Maui HPCC Johnson group (Yale, 2003) Searcy and Fenn (1974) Magic numbers at n = 6, 21, and possibly at 24, 26, 28 in the mass spectra of H+(H2O)n clusters n=6 n=21 n=28 n=21

Mass spectra H+(H₂O)n clusters n = 2-30

hv Vibrational predissociation spectroscopy (Johnson and Duncan groups)

• Greatly increased sensitivity over simple absorption spectroscopy

• Ar-tagged clusters tend to be appreciably colder (T ≈ 140 K), yielding simpler spectra

H+(H2O)n H+(H2O)n-1 + H2O hv H+(H2O)n + Ar H+(H2O)nAr n = 1-15

Last few years – the combination of experiments and theory has led to significant advances in our understanding of the properties of protonated water clusters

1. Shin, Hammer, Diken, Johnson, Walters, Jaeger, Duncan, Christie, Jordan: Science 2004.

2. Miyazaki, Fujii, Ebatu, Mikami: Science 2004.

3. Wu, Lin, Chang, Jiang, Kuo, Klein: JCP 2005.

4. Lin, Wu, Wang, Lee, Chang, Kuo, Klein, PCCP 2005.

5. Lisy, unpublished results.