eprintid: 16165 rev_number: 26 userid: 1291 dir: disk0/00/01/61/65 datestamp: 2012-11-12 14:56:01 lastmod: 2021-06-12 22:55:16 status_changed: 2012-11-12 14:56:01 type: article metadata_visibility: show item_issues_count: 0 eprint_status: archive creators_name: Douberly, GE creators_name: Walters, RS creators_name: Cui, J creators_name: Jordan, KD creators_name: Duncan, MA creators_email: creators_email: creators_email: creators_email: jordan@pitt.edu creators_email: creators_id: creators_id: creators_id: creators_id: JORDAN creators_id: title: Infrared spectroscopy of small protonated water clusters, H +(H2O)n (n = 2-5): Isomers, argon tagging, and deuteration ispublished: pub divisions: sch_as_chemistry full_text_status: public abstract: Infrared photodissociation spectroscopy is reported for mass-selected H+(H2O)n complexes and their deuterated analogues with and without argon "tagging." H+(H 2O)nArm and D+(D2O) nArm complexes are studied in the O-H (O-D) stretching region for clusters in the small size range (n = 2-5). Upon infrared excitation, these clusters fragment by the loss of either argon atoms or one or more intact water molecules. Their excitation spectra show distinct bands in the region of the symmetric and asymmetric stretches of water and in the hydrogen bonding region. Experimental studies are complemented by computational work that explores the isomeric structures, their energetics and vibrational spectra. The addition of an argon atom is essential to obtain photodissociation for the n = 2-3 complexes, and specific inclusion of the argon in calculations is necessary to reproduce the measured spectra. For n = 3-5, spectra are obtained both with and without argon. The added argon atom allows selection of a subset of colder clusters and it increases the photodissociation yield. Although most of these clusters have more than one possible isomeric structure, the spectra measured correspond to a single isomer that is computed to be the most stable. Deuteration in these small cluster sizes leads to expected lowering of frequencies, but the spectra indicate the presence of the same single most-stable isomer for each cluster size. © 2010 American Chemical Society. date: 2010-04-08 date_type: published publication: Journal of Physical Chemistry A volume: 114 number: 13 pagerange: 4570 - 4579 refereed: TRUE issn: 1089-5639 id_number: 10.1021/jp100778s pmid: 20232806 mesh_headings: Argon--chemistry mesh_headings: Binding Sites mesh_headings: Computational Biology mesh_headings: Deuterium--chemistry mesh_headings: Hydrogen Bonding mesh_headings: Isomerism mesh_headings: Photochemistry mesh_headings: Protons mesh_headings: Spectrophotometry, Infrared mesh_headings: Thermodynamics mesh_headings: Water--chemistry chemical_names: Protons chemical_names: Argon chemical_names: Water chemical_names: Deuterium citation: Douberly, GE and Walters, RS and Cui, J and Jordan, KD and Duncan, MA (2010) Infrared spectroscopy of small protonated water clusters, H +(H2O)n (n = 2-5): Isomers, argon tagging, and deuteration. Journal of Physical Chemistry A, 114 (13). 4570 - 4579. ISSN 1089-5639 document_url: http://d-scholarship-dev.library.pitt.edu/16165/1/licence.txt