The properties and nature of water clusters studied with novel spectroscopic approaches are presented in this thesis. Following a general introduction on the chemistry of water and water clusters, detailed descriptions of the experiments and analyses are given. All the experimental results, including first size-selective spectra of large clusters consisting of 200 water molecules, are presented with corresponding analyses. Hitherto unidentified hydrogen bond network structures, dynamics, and reactivity of various water clusters have been characterized at the molecular level. The main targets of this book are physical chemists and chemical physicists who are interested in water chemistry or cluster chemistry. From the Back Cover The properties and nature of water clusters studied with novel spectroscopic approaches are presented in this thesis. Following a general introduction on the chemistry of water and water clusters, detailed descriptions of the experiments and analyses are given. All the experimental results, including first size-selective spectra of large clusters consisting of 200 water molecules, are presented with corresponding analyses. Hitherto unidentified hydrogen bond network structures, dynamics, and reactivity of various water clusters have been characterized at the molecular level. The main targets of this book are physical chemists and chemical physicists who are interested in water chemistry or cluster chemistry. About the Author Kenta Mizuse, Ph.D. Date of Birth: February 16, 1984 Place of Birth: Niigata, Japan Nationality: Japan Since April 2011 Department of Photo-Molecular Science (Prof. Yasuhiro Ohshima’s Lab.), Institute for Molecular Science, Japan Assistant professor April 2008-March 2011 The Japan Society for the Promotion of Science (JSPS) Research fellow April 2006-March 2011 Department of Chemistry, Graduate School of Science, Tohoku University, Japan Ph.D. student Supervisor: Professor Asuka Fujii Degree obtained: Ph.D. in Science April 2002-March 2006 Department of Chemistry, Faculty of Science, Tohoku University, Japan Undergraduate student Supervisor: Professor Naohiko Mikami Publications 1 Mizuse, K. & Fujii, A. Infrared Spectroscopy of Large Protonated Water Clusters H+(H2O)20-50 Cooled by Inert Gas Attachment. Chem. Phys. in press, doi:10.1016/j.chemphys.2012.07.012 (2013). 2 Mizuse, K. & Fujii, A. Tuning of the Internal Energy and Isomer Distribution in Small Protonated Water Clusters H+(H2O)4–8: An Application of the Inert Gas Messenger Technique. J. Phys. Chem. A 116, 4868-4877 (2012). 3 Mizuse, K., Suzuki, Y., Mikami, N. & Fujii, A. Solvation-Induced σ-Complex Structure Formation in the Gas Phase: A Revisit to the Infrared Spectroscopy of [C6H6–(CH3OH)2]+. J. Phys. Chem. A 115, 11156-11161 (2011). 4 Mizuse, K., Kuo, J.-L. & Fujii, A. Structural trends of ionized water networks: Infrared spectroscopy of water cluster radical cations (H2O)n+ (n = 3-11). Chem. Sci. 2, 868-876 (2011). 5 Mizuse, K. & Fujii, A. Structural Origin of the Antimagic Number in Protonated Water Clusters H+(H2O)n: Spectroscopic Observation of the “Missing” Water Molecule in the Outermost Hydration Shell. J. Phys. Chem. Lett. 2, 2130-2134 (2011). 6 Mizuse, K. & Fujii, A. Infrared photodissociation spectroscopy of H+(H2O)6·Mm (M = Ne, Ar, Kr, Xe, H2, N2, and CH4): messenger-dependent balance between H3O+ and H5O2+ core isomers. Phys. Chem. Chem. Phys. 13, 7129-7135 (2011). 7 Hamashima, T., Mizuse, K. & Fujii, A. Spectral Signatures of Four-Coordinated Sites in Water Clusters: Infrared Spectroscopy of Phenol-(H2O)n (~20 ≤ n ≤ ~50). J. Phys. Chem. A 115, 620-625 (2011). 8 Mizuse, K., Mikami, N. & Fujii, A. Infrared Spectra and Hydrogen-Bonded Network Structures of Large Protonated Water Clusters H+(H2O)n (n=20-200). Angew. Chem. Int. Ed. 4