1. How Do Networks of Water Accommodate an Excess Electron?, Joseph R. Roscioli, and Mark A. Johnson Nathan I. Hammer, Joseph R. Roscioli, and Mark A. Johnson Yale University International Symposium on Molecular Spectroscopy 60 th Meeting – June 20-24, 2005 60 th Meeting – June 20-24, 2005

2. Kit Bowen Mark Johnson Jim Coe Dan Neumark Photoelectron Spectra Reveal Three Isomer Classes of (H 2 O) n  J. V. Coe, et al., J. Chem. Phys., 92, 3980 (1990) J. Kim, et al., Chem. Phys. Lett., 297, 91 (1998) J. –W. Shin, et al., Chem. Phys. Lett., 399, 349 (2004) J. R. R. Verlat, et al., Science, 309, 93 (2005) N. I. Hammer, et al., J. Phys. Chem. A, accepted (2005) Water Cluster FD11 – 11:42 Bulk ?

3. mid- IR (600-4500 cm -1 ) 500 mJ 10 Hz YAG 1064 nm OPO/OPA MCP ion detector MCP neutral detector reflectron valve pulsed 1 keV electron gun ion beam drift tube YAG PES detector 1064 nm photo- electrons L.M. Posey and M.A. Johnson, J. Chem. Phys., 88, 5383 (1988) Synthesizing and Studying (H 2 O) n  and (H 2 O) n  ·Ar m

4. 110012001300 Photon Energy (cm -1 ) (D 2 O) 6 - (D 2 O) 4 - (D 2 O) 3 - Isomer I Binds the Electron Primarily by One Water Molecule N. I. Hammer, et al., Science, 306, 675 (2004)

5. How Do the Weaker Isomer Classes Bind the Excess Electron? 234567891011 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Isomer III Isomer II Electron Binding Energy (eV) Water Cluster Size n Isomer I AA Motif ? OH 0.00.20.40.60.81.0 (H 2 O) 6  Electron Binding Energy (eV) I II OH OD HOH DOD Photoelectron Spectrum

6. 110012001300 (D 2 O) 6  ·Ar 2 Photon Energy (cm  1 ) Electron Binding Energy (eV) 0.00.20.40.60.81.0 I II 10 Ar 6 Ar 2 Ar (D 2 O) 6 ¯ * 1500160017001800 Photon Energy (cm  1 ) (H 2 O) 6  ·Ar 4 Isomer I Only!

7. 110012001300 110012001300 Photon Energy (cm  1 ) AD AAD AA AAD AD ADD Isomer II Isomer I ADD AD AA AAD ADD AD AAD How Does Isomer II Bind the Excess Electron?

8. How High Up in Size Do the Electron Binding Motifs Persist?

9. Johnson Lab Prof. Mark A. Johnson Prof. Gary H. Weddle (Fairfield U.) Dr. Joong-Won Shin Eric G. Diken Jeffrey M. Headrick Joseph R. Roscioli Joseph C. Bopp Kevin C. Jones Acknowledgements Dan Neumark Kit Bowen Ken Jordan John Herbert

11. “Book” Neutral “Armchair” Anion “Book” Anion “Book” AA Anion How are the Anions Created?

12. AA vs. Collective High dipole moment Bound to one side of cluster Requires much rearrangement from neutral clusters Low dipole moment Bound to one side of cluster or can be internally solvated in cage of water molecules Requires little rearrangement from neutral clusters Comparing the Two Electron Binding Motifs

13. AA Collective Examples of the Two Electron Binding Motifs