Characterization of an activated iridium water splitting catalyst using infrared predissociation of H₂ tagged ions.
Etienne Garand, Joseph A. Fournier, Michael Z. Kamrath, Nathan D. Schley, Robert H. Crabtree, and Mark A. Johnson Phys. Chem. Chem. Phys., Submitted.

Isomer-specific IR-IR double resonance spectroscopy of D₂-tagged protonated dipeptides prepared in a cryogenic ion trap
Christopher M. Leavitt, Arron B. Wolk, Joseph A. Fournier, Michael Z. Kamrath, Etienne Garand, Michael J. Van Stipdonk, and Mark A. Johnson J. Phys. Chem. Lett., 3, 1099-1105, 2012.

Vibrational Fano resonances in dipole-bound anions
Stephen Edwards, Mark Johnson, and John Tully J. Chem. Phys., 136, 154305, 2012.

Vibrational manifestations of strong non-Condon effects in the H₃O⁺•X₃ (X=Ar, N₂, CH₄, H₂O) complexes: Microscopic analogues of the "association band" in the vibrational spectrum of water
Anne B. McCoy, Timothy L. Guasco, Christopher M. Leavitt, Solveig G. Olesen, and Mark A. Johnson Phys. Chem. Chem. Phys., 14, 7205-7214, 2012.

Characterization of highly unusual NH⁺-O hydrogen bonding to ester ether oxygen atoms through spectroscopic and computational studies
Michael T. Scerba, Andrew F. DeBlase, Steven Bloom, Travis Dudding, Mark A. Johnson, and Thomas Lectka, J. Phys. Chem. A, ASAP DOI:10.1021/jp211688v.

Structural characterization of electron-induced proton transfer in the formic acid dimer anion, (HCOOH)₂^¯, with vibrational and photoelectron spectroscopies
Helen K. Gerardi, Andrew F. DeBlase, Christopher M. Leavitt, Xiaoge Su, Kenneth D. Jordan, Anne B. McCoy, and Mark A. Johnson, J. Chem. Phys, 136, 134318, 2012.

Water
Robert G. Bryant, Mark A. Johnson, and Peter J. Rossky, Acc. Chem. Res., 45 (1), 1-2, 2012.

Determination of noncovalent docking by IR spectroscopy of cold gas-phase complexes
Etienne Garand, Michael Z. Kamrath, Peter A. Jordan, Arron B. Wolk, Christopher M. Leavitt, Anne B. McCoy, Scott J. Miller, and Mark A. Johnson, Science, 355 (6069), 694-698, 2012.

A bottom-up view of water network-mediated CO₂ reduction using cryogenic cluster ion spectroscopy and direct dynamics simulations
Kristin J. Breen, Andrew F. DeBlase, Timothy L. Guasco, Vamsee K. Voora, Kenneth D. Jordan, Takashi Nagata, and Mark A. Johnson, J. Phys. Chem. A, 116 (3), 903-912, 2012. (Invited Article, Feature Cover Article)

Unraveling the anomalous solvatochromic response of the formate ion vibrational spectrum: An infrared, Ar-tagging study of the HCO₂^¯, DCO₂^¯, and HCO₂^¯•H₂O ions
Helen K. Gerardi, Andrew F. DeBlase, Xiaoge Su, Kenneth D. Jordan, Anne B. McCoy, and Mark A. Johnson, J. Phys. Chem. Lett., 2, 2437-2441, 2011.

NH⁺-F hydrogen bonding in a fluorinated "proton sponge" derivative: Integration of solution, solid state, gas phase and computational studies
Michael Scerba, Christopher Leavitt, Matthew Diener, Andrew DeBlase, Timothy Guasco, Maxime Siegler, Nathaniel Bair, Mark Johnson, and Thomas Lectka, J. Org. Chem., 76 (19), 7975-7984, 2011.

Characterizing the intramolecular H-bond and secondary structure in methylated GlyGlyH⁺ with H₂ predissociation spectroscopy
Christopher M. Leavitt, Arron B. Wolk, Michael Z. Kamrath, Etienne Garand, Michael J. Van Stipdonk, and Mark A. Johnson, J. Am. Soc. Mass Spectrom., 22 (11), 1941-1952, 2011.

Tuning the intermolecular proton bond in the H₅O₂⁺ "Zundel ion" scaffold
Solveig G. Olesen, Timothy L. Guasco, Joseph R. Roscioli, and Mark A. Johnson, Chem. Phys. Lett., 509 (4-6), 89-95, 2011. (Frontiers Article, Cover Article)

The importance of NO⁺(H₂O)₄ in the conversion of NO⁺(H₂O)_n to H₃O⁺(H₂O)_n: I. Kinetics measurements and statistical rate modeling
Nicole Eyet, Nicholas S. Shuman, Albert A. Viggiano, Jürgen Troe, Rachael A. Relph, Ryan P. Steele, and Mark A. Johnson, J. Phys. Chem. A, 115 (26), 7582-7590, 2011.

Vibrational characterization of simple peptides using cryogenic infrared photodissociation of H₂-tagged, mass-selected ions
Michael Z. Kamrath, Etienne Garand, Peter A. Jordan, Christopher M. Leavitt, Arron B. Wolk, Michael J. Van Stipdonk, Scott J. Miller, and Mark A. Johnson, J. Am. Chem. Soc., 133 (16), 6440-6448, 2011.

Unraveling anharmonic effects in the vibrational predissociation spectra of H₅O₂⁺ and its deuterated analogues
Timothy L. Guasco, Anne B. McCoy, and Mark A. Johnson, J. Phys. Chem. A, 115 (23), 5847-5858, 2011.

Vibrational predissociation spectroscopy of the H₂-tagged mono- and dicarboxylate anions of dodecanedioic acid
Michael Z. Kamrath, Rachael A. Relph, Timothy L. Guasco, Christopher M. Leavitt, and Mark A. Johnson, Int. J. Mass Spectrom., 300 (2-3), 91-98, 2011.

Vibrational predissociation spectroscopy and theory of Ar-tagged, protonated Imidazole (Im) Im_1-3H⁺·Ar clusters
Helen K. Gerardi, George H. Gardenier, Usha Viswanathan, Scott M. Auerbach, and Mark A. Johnson, Chem. Phys. Lett., 501 (4-6), 172-178, 2011.

Vibrational predissociation spectrum of the carbamate radical anion, C₅H₅N-CO₂^¯, generated by reaction of pyridine with (CO₂)_m^¯
Michael Z. Kamrath, Rachael A. Relph, and Mark A. Johnson, J. Am. Chem. Soc., 132 (44), 15508-15511, 2010.

Downsizing the Hydrated Electron's Lair
Kenneth D. Jordan and Mark A. Johnson, Science, 329, 42-43, 2010.

Isolating the spectral signatures of individual sites in water networks using vibrational double-resonance spectroscopy of cluster isotopomers
Timothy L. Guasco, Ben M. Elliott, Mark A. Johnson, Jing Ding and Kenneth D. Jordan, J. Phys. Chem. Lett., 1, 2396-2401, 2010.

Vibrational Predissociation Spectra of the Ar-Tagged [CH₄ · H₃O⁺] binary complex: Spectroscopic Signature of hydrogen bonding to an alkane
Solveig Gaarn Olesen, Timothy L. Guasco, Gary H. Weddle, Steen Hammerum, and Mark A. Johnson, Mol. Phys., 108 (7), 1191-1197, 2010.

Tribute to W. Carl Lineberger
Mark A. Johnson and Anne B. McCoy, J. Phys. Chem. A, 114 (3), 1225-1226, 2010.

Survey of Ar-tagged predissociation and vibrationally mediated photodetachment spectroscopies of the vinylidene anion, C₂H₂^-
Helen K. Gerardi, Kristin J. Breen, Timothy L. Guasco, Gary H. Weddle, George H. Gardenier, Jennifer E. Laaser, and Mark A. Johnson, J. Phys. Chem. A, 114 (3), 1592-1601, 2010.

Anharmonicities and isotopic effects in the vibrational spectra of X^-·H2O, ·HDO, and ·D2O [X = Cl, Br, and I] binary complexes
Samantha Horvath, Anne B. McCoy, Ben M. Elliott, Gary H. Weddle, Joseph R. Roscioli, and Mark A. Johnson, J. Phys. Chem. A, 114 (3), 1556-1568, 2010.

How the shape of an H-bonded network controls proton-coupled water activation in HONO formation
Rachael A. Relph, Timothy L. Guasco, Ben M. Elliott, Michael Z. Kamrath, Anne B. McCoy, Ryan P. Steele, Daniel P. Schofield, Kenneth D. Jordan, Albert A. Viggiano, Eldon E. Ferguson and Mark A. Johnson, Science, 327, 308-312, 2010.

Structural Characterization of (C₂H₂)_1-6⁺ Cluster Ions by Vibrational Predissociation Spectroscopy
Rachael A. Relph, Joseph C. Bopp, Joseph R. Roscioli, and Mark A. Johnson, J. Chem. Phys., 131, 114305, 2009.

Structural Evolution of the [(CO₂)_n(H₂O)]^- Cluster Anions: Quantifying the Effect of Hydration on the Excess Charge Accommodation Motif
Azusa Muraoka, Yoshiya Inokuchi, Nathan I. Hammer, Joong-Won Shin, Takashi Nagata, and Mark A. Johnson, J. Phys. Chem. A, 113 (31), 8942-8948, 2009.

Experiment and Theory in Harmony
Mark A. Johnson, Nature Chemistry, Feature Article for the inaugural issue April 1, 2009. 1, 8 - 9, 2009.

Generating spectra from ground state wave functions: Unraveling anharmonic effects in the OH^-(H₂O) vibrational predissociation spectrum
Anne B. McCoy, Eric G. Diken, and Mark A. Johnson, J. Phys. Chem. A, 113 (26), 7346-7352, 2009.

Vibrational predissociation spectra of the O_n^-, n = 3 - 10, 12 clusters: Even-odd alternation in the core ion
Joseph C. Bopp, Anastassia N. Alexandrova, Ben M. Elliott, Tobias Herden, and Mark A. Johnson, Int. J. Mass Spectrom., 283, 94–99, 2009.

Spectroscopic study of the ion-radical H-bond in H₄O₂⁺
George H. Gardenier, Mark A. Johnson, and Anne B.McCoy, J. Phys. Chem. A, 113 (16), 4772–4779, 2009.

Photoelectron imaging study of vibrationally mediated electron autodetachment in the type I isomer of the water hexamer anion
Ben M. Elliott, Laura R. McCunn, and Mark A. Johnson, Chem. Phys. Lett., 467, 32-36, 2008.

Vibrationally-induced interconversion of H-bonded NO₂^{- .} H₂O isomers within NO₂^{- .} H₂O ^. Ar_m clusters using IR-IR pump-probe through the OH and NO stretching vibrations
Rachael A. Relph, Ben M. Elliott, Gary H. Weddle, Mark A. Johnson, Jing Ding and Kenneth D. Jordan, J. Phys. Chem. A., 113 (6), 975-981, 2009.

Vibration induced proton transfer in F^-(H₂O) and F^-(D₂O)
Samantha Horvath, Anne McCoy, Joseph R. Roscioli, and Mark A. Johnson, J. Phys. Chem. A, 112 (48), 12337–12344, 2008.

Isolating the spectra of cluster ion isomers using Ar-“tag”-mediated IR-IR double resonance within the vibrational manifolds: Application to NO₂^{- .} H₂O
Ben M. Elliott, Rachael A. Relph, Joseph R. Roscioli, Joseph C. Bopp, George H. Gardenier, Timothy L. Guasco, Mark A. Johnson, J. Chem. Phys., 129, 094303, 2008.

Argon cluster-mediated isolation and vibrational spectra of peroxy and nominally D_3h isomers of CO₃^- and NO₃^-
Rachael A. Relph, Joseph C. Bopp, and Mark A. Johnson, J. Chem. Phys., 129, 064305, 2008.

Why does argon bind to deuterium? Isotope effects and structures of Ar ^. H₅O₂⁺ complexes
Laura R. McCunn, Joseph R. Roscioli, Ben M. Elliott, Mark A. Johnson and Anne B. McCoy, J. Phys. Chem. A, 112 (27), 6074-6078, 2008.

Intermolecular proton binding in the presence of a large electric dipole: Ar-tagged vibrational predissociation spectroscopy of CH₃CN^.H^+.OH₂ and CH₃CN^.H^+.OD₂ complexes
George H. Gardenier, Joseph R. Roscioli, and Mark A. Johnson, J. Phys. Chem. A, 112 (47), 12022-12026, 2008.

Probing isomer interconversion in anionic water clusters using an Ar-mediated pump-probe approach: Combining vibrational predissociation and velocity-map photoelectron imaging spectroscopies
Laura R. McCunn, George H. Gardenier, Timothy L. Guasco, Ben M. Elliott, Joseph C. Bopp, Rachael A. Relph, and Mark A. Johnson J. Chem. Phys., 128, 234311, 2008.

Site-specific addition of D₂O to the (H₂O)₆^- “hydrated electron” cluster: Isomer interconversion and substitution at the double H-bond acceptor (AA) electron-binding site
Laura R. McCunn, Jeffrey M. Headrick and Mark A. Johnson, Phys. Chem. Chem. Phys., 10, 3118, 2008.

Exploring the correlation between network structure and electron binding energy in the (H₂O)₇^- cluster through isomer photoselected vibrational predissociation spectroscopy and ab initio calculations: Addressing complexity beyond types I-III
J. R. Roscioli, N. I. Hammer, M. A. Johnson, K. Diri and K. D. Jordan, J. Chem. Phys., 128, 104314, 2008.

An H/D isotopic substitution study of the H₅O₂⁺·Ar vibrational predissociation spectra: Exploring the putative role of Fermi resonances in the bridging proton fundamentals
Laura R. McCunn, Joseph R. Roscioli, Mark A. Johnson, and Anne B. McCoy, J. Phys. Chem. B, 112, 321-327, 2008.

Gas-Phase Infrared Spectroscopy and Multidimensional Quantum Calculations of the Protonated Ammonia Dimer N₂H₇⁺
K. R. Asmis, Y. Yang, G. Santambrogio, M. Brümmer, J. R. Roscioli, L. R. McCunn, M. A. Johnson, O. Kühn, Angewandte Chemie Int. Ed., 46, 8691-8694, 2007.

Theoretical and infrared spectroscopic investigation of the O₂^-·benzene and O₄^-·benzene complexes
Holger Schneider, J. Mathias Weber, Evgeniy M. Myshakin, Kenneth D. Jordan, Joseph Bopp, Tobias Herden and Mark A. Johnson, J. Chem. Phys., 127, 084319, 2007.

Kinetics for the Reactions of O^- and O₂^- with O₂(a¹Δ_g) Measured in a Selected Ion Flow Tube at 300 K
Anthony Midey, Itzhak Dotan, S. Lee, W. T. Rawlins, Mark A. Johnson, and A. A. Viggiano, J. Phys. Chem. A, 111, 5218, 2007.

Infrared Multiple Photon Dissociation of the Hydrated Electron Clusters (H₂O)_15-50^-
Knut R. Asmis, Gabriele Santambrogio, Jia Zhou, Etienne Garand, Jeffrey Headrick, Daniel Goebbert, Mark A. Johnson, Daniel M. Neumark, J. Chem. Phys., 126, 191105, 2007.

Quantum structure of the intermolecular proton bond
J. R. Roscioli, L. R. McCunn and M. A. Johnson, Science, 316, 249-254, 2007.

Spectroscopic characterization of the isolated SF₆^- and C₄F₈^- anions: Observation of very long harmonic progressions in symmetric deformation modes upon photodetachment
Joseph C. Bopp, Joseph R. Roscioli, Mark A. Johnson, T. M. Miller, A. A. Viggiano, S. M. Villano, S. W. Wren, and W. C. Lineberger, J. Phys. Chem. A , 111, 1214-1221, 2007.

Isomer-specific spectroscopy of the (H₂O)₈^- cluster anion in the intramolecular bending region by selective photodepletion of the more weakly electron binding species (isomer II)
Joseph R. Roscioli and Mark A. Johnson, J. Chem. Phys., 126, 024307, 2007.

Infrared spectroscopy of water cluster anions, (H₂O)_n=3-24^- in the HOH bending region: Persistence of the double H-bond acceptor (AA) water molecule in the excess electron binding site of the class I isomers
Joseph R. Roscioli, Nathan I. Hammer, and Mark A. Johnson, J. Phys. Chem. A, 110, 7517, 2006.

Determination of the CO₃^- Bond Strength via the Resonant Two-Photon Photodissociation Threshold: Electronic and Vibrational Spectroscopy of CO₃^- · Ar_n
Joseph C. Bopp, Eric G. Diken, Jeffrey M. Headrick, Joseph R. Roscioli, Mark A. Johnson, Anthony J. Midey, and A. A. Viggiano, J. Chem. Phys., 124, 174302, 2006.

Prying apart a water molecule with anionic H-bonding: A comparative spectroscopic study of the X^-·H₂O (X = OH, O, F, Cl, and Br) binary complexes in the 600 - 3800 cm^-1 region
Joseph R. Roscioli, Eric G. Diken, Mark A. Johnson, Samantha Horvath, and A. B. McCoy, J. Phys. Chem. A , 110, 4943-4952, 2006. (Feature Article, Cover Article)

Vibrational predissociation spectroscopy of the (H₂O)_6-21^- clusters in the OH stretching region: Evolution of the excess electron binding signature into the intermediate cluster size regime
Nathan I. Hammer, Joseph R. Roscioli, Joseph C. Bopp, Jeffrey M. Headrick and Mark A. Johnson, J. Chem. Phys., 123, 244311, 2005.

Mid infrared characterization of the NH₄⁺· (H₂O)_n clusters in the neighborhood of the n = 20 magic number
E.G. Diken, N.I. Hammer, M.A. Johnson, R.A. Christie, and K.D. Jordan, J. Chem. Phys., 123, 164309, 2005.

Infrared spectrum and structural assignment of the water trimer anion
N.I. Hammer, J.R. Roscioli, M.A. Johnson, E.M. Myshakin, and K.D. Jordan J. Phys. Chem. A, 109, 11526-11530, 2005.

Identification of two distinct electron binding motifs in the anionic water clusters: A vibrational spectroscopic study of the (H₂O)₆^- isomers
N.I. Hammer, J.R. Roscioli, and M.A. Johnson, J. Phys. Chem. A, 109, 7896-7901, 2005.

Spectral signatures of hydrated proton vibrations in water clusters
J.M. Headrick, E.G. Diken, R.S. Walters, N.I. Hammer, R.A. Christie, J. Cui, E.M. Myshakin, M.A. Duncan, M.A. Johnson, and K.D. Jordan, Science, 308, 1765-1769, 2005.

Vibrational predissociation spectra of the H₅O₂⁺· RG_n (RG = Ar, Ne) clusters: Correlation of the solvent perturbations in the free OH and shared proton transitions of the Zundel ion
N.I. Hammer, E.G. Diken, J.R. Roscioli, E.M. Myshakin, K.D. Jordan, A.B. McCoy, X. Huang, S. Carter, J.M. Bowman, and M.A. Johnson, J. Chem. Phys., 122, 244301, 2005.

An infrared investigation of the (CO₂)_n^- clusters: Core ion switching from both the ion and solvent perspectives
J-W. Shin, N.I. Hammer, M.A. Johnson, H. Schneider, A. Glob, and J.M. Weber, J. Phys. Chem. A, 109, 3146-3152, 2005.

Fundamental excitations of the shared proton in the H₃O₂^- and H₅O₂⁺ complexes
Eric G. Diken, Jeffrey M. Headrick, Joseph R. Roscioli, Joseph C. Bopp, Mark A. Johnson, and Anne B. McCoy J. Phys. Chem. A, 109, 1487-1490, 2005.

Role of Water in Electron-Initiated Processes and Radical Chemistry: Issues and Scientific Advances
Bruce C. Garrett, David A. Dixon, Donald M. Camaioni, Daniel M. Chipman, Mark A. Johnson, Charles D. Jonah, Gregory A. Kimmel, John H. Miller, Thomas N. Rescigno, Peter J. Rossky, Sotiris S. Xantheas, Steven D. Colson, Allan H. Laufer, Douglas Ray, Paul F. Barbara, David M. Bartels, Kurt H. Becker, Kit H. Bowen, Jr., Stephen E. Bradforth, Ian Carmichael, James V. Coe, L. Rene Corrales, James P. Cowin, Michel Dupuis, Kenneth B. Eisenthal, James A. Franz, Maciej S. Gutowski, Kenneth D. Jordan, Bruce D. Kay, Jay A. LaVerne, Sergei V. Lymar, Theodore E. Madey, C. William McCurdy, Dan Meisel, Shaul Mukamel, Anders R. Nilsson, Thomas M. Orlando, Nikolay G. Petrik, Simon M. Pimblott, James R. Rustad, Gregory K. Schenter, Sherwin J. Singer, Andrei Tokmakoff, Lai-Sheng Wang, Curt Wittig, and Timothy S. Zwier , Chem. Rev., 105, 355-390, 2005.

Argon predissociation spectroscopy of the OH^-· H₂O and Cl^-· H₂O complexes in the 1000 - 1900 cm^-1 region: Intramolecular bending transitions and the search for the shared proton fundamental in the hydroxide monohydrate
Eric G. Diken, Jeffrey M. Headrick, Joseph R. Roscioli, Joseph C. Bopp, Mark A. Johnson, Anne B. McCoy, Xinchuan Huang, Stuart Carter, and Joel M. Bowman, J. Phys. Chem. A, 109, 571-575, 2005.

Photoelectron spectroscopy of the [Glycine· (H₂O)_1,2]^- clusters: Sequential hydration shifts and observation of isomers
Eric G. Diken, Jeffrey M. Headrick, and Mark A. Johnson, J. Chem. Phys., 122, 224317-1-6, 2005.

Predissociation spectroscopy of the argon-solvated H₅O₂⁺ "Zundel" cation in the 1000 - 1900 cm^-1 region
Jeffrey M. Headrick, Joseph C. Bopp, and Mark A. Johnson, J. Chem. Phys., 121, 11523-11526, 2004.

How do small water clusters bind an excess electron?
Nathan I. Hammer, Joong-Won Shin, Jeffrey M. Headrick, Eric G. Diken, Joseph R. Roscioli, Gary H. Weddle, and Mark A. Johnson Science, 306, 675-679, 2004. (SciencExpress)

Argon cluster-mediated trapping and vibrational spectroscopic characterization of an OH^-· HCH₂· intermediate in the O· ^- + CH₄ reaction
Eric G. Diken, Gary H. Weddle, Jeffrey M. Headrick, J. Mathias Weber, and Mark A. Johnson, J. Phys. Chem. A, 108, 10116-10121, 2004.

Preparation and photoelectron spectrum of the "missing" (H₂O)₄^- cluster
Joong-Won Shin, Nathan I. Hammer, Jeffrey M. Headrick, and Mark A. Johnson, Chem. Phys. Lett., 399, 349-353, 2004.

Preparation and photoelectron spectrum of the glycine molecular anion: Assignment to a dipole-bound electron species with a high-dipole moment, non-zwitterionic form of the neutral core
Eric G. Diken, Nathan I. Hammer, and Mark A. Johnson, J. Chem. Phys., 120, 9899-9902, 2004.

Infrared signature of structures associated with the H⁺(H₂O)_n, n = 6-27, clusters
Joong-Won Shin, Nathan I. Hammer, Eric G. Diken, Mark A. Johnson, Richard S. Walters, Todd D. Jaeger, Michael A. Duncan, Richard A. Christie, and Kenneth D. Jordan, Science, 304, 1137-1140, 2004. (SciencExpress)

Isotopic Fractionation and Zero-Point Effects in Anionic H-Bonded Complexes: A Comparison of the I^-· HDO and F^-· HDO Ion-Molecule Clusters
Eric G. Diken, Joong-Won Shin, Erica A. Price, and Mark A. Johnson, Chem. Phys. Lett., 387, 17-22, 2004.

A cluster study of Cl₂^- microhydration: Size-dependent competition between symmetrical H-bonding to the anion and the formation of cyclic water networks in the Cl₂^-· 1-5(H₂O) series
Erica A. Price, Nathan I. Hammer, and Mark A. Johnson, J. Phys. Chem. A, 108, 3910-3915, 2004.

The vibrational spectrum of the neutral (H₂O)₆ precursor to the "magic" (H₂O)₆^- cluster anion by argon-mediated, population-modulated electron attachment spectroscopy
Eric G. Diken, William H. Robertson, and Mark A. Johnson, J. Phys. Chem. A, 108, 64-68, 2004.

Large Anharmonic Effects in the Infrared Spectra of the Symmetrical CH₃NO₂^-· (H₂O) and CH₃CO₂^-· (H₂O) Complexes
E.M. Myshakin, K.D. Jordan, E.L. Sibert III, and Mark A. Johnson, J. Chem. Phys., 119, 10138-10145, 2003.

Snapshots of Water at Work
William H. Robertson, Eric G. Diken, Mark A. Johnson, Science, 301, 320-321, 2003.

Strong similarities in the local hydration environments of the bromide ion and the Cl^-· CCl₃^· ion-radical complex: Factors contributing to intramolecular distortions in the primary hydration shell
William H. Robertson, Gary H. Weddle, and Mark A. Johnson, J. Phys. Chem. A, 107, 9312-9318, 2003.

Infrared signatures of a water molecule attached to triatomic domains of molecular anions: Evolution of the H-bonding configuration with domain length
William H. Robertson, Erica A. Price, J. Mathias Weber, Joong-Won Shin, Gary H. Weddle, and Mark A. Johnson, J. Phys. Chem. A, 107, 6527-6532, 2003.

Spectroscopic Determination of the OH^- Solvation Shell in the OH^-· (H₂O)_n Clusters
William H. Robertson, Eric G. Diken, Erica A. Price, Joong-Won Shin, Mark A. Johnson, Science, 299, 1367-1372, 2003.

Molecular Aspects of Halide Ion Hydration: The Cluster Approach
William H. Robertson, Mark A. Johnson, Annual Review of Physical Chemistry, 54, 173-213, 2003.

Dominant structural motifs of NO^-· (H₂O)_n complexes: Infrared spectroscopic and ab initio studies
Evgeniy M. Myshakin, William H. Robertson, Gary H. Weddle, Kenneth D. Jordan, Mark A. Johnson, J. Chem. Phys., 118, 4945-4953, 2003.

Caught in the Act of Dissolution
William H. Robertson, Mark A. Johnson, Science, 298, 69, 2002.

Vibrational Predissociation Ion Spectroscopy
Mark A. Johnson, Encyclopedia of Mass Spectrometry, Vol. 5, 2002.

Van der Waals clusters and mass spectrometry: meeting the challenge of size-dependence in the nanosolvation regime
M. A. Johnson and T. D. Mark, Int. Journal of Mass Spectrometry, 220, 2, 97-98, 2002.

Infrared spectroscopic characterization of the symmetrical hydration motif in the SO₂^-· H₂O complex
Erica A. Woronowicz, William H. Robertson, Gary H. Weddle, Evgeniy Myshakin, Kenneth D. Jordan, Mark A. Johnson, J. Phys. Chem. A, 106, 7086-7089, 2002.

Isolating the charge-transfer component of the anionic H-bond via spin suppression of the intra-cluster proton transfer reaction in the NO^-· H₂O entrance channel complex
William H. Robertson, Yevgeniy Myshakin, Kenneth D. Jordan, Mark A. Johnson, J. Phys. Chem. A, 106, 10010-10014, 2002.

Observation of sharp vibronic bands in the O₄^- "core ion" by mid infrared predissociation spectroscopy of O₄^-· Ar_n clusters
Jude A. Kelley, William H. Robertson and Mark A. Johnson, Chem. Phys. Lett., 362, 255-260, 2002.

Infrared predissociation spectroscopy of I^-· (CH₃OH)_n, n = 1,2:  Cooperativity in asymmetric solvation
W. H. Robertson, K. Karapetian, P. Ayotte, K. D. Jordan, and M. A. Johnson, J. Chem. Phys., 116, 12, 4853-4857, 2002.

Infrared Characterization of the Icosahedral Shell Closing in Cl^-· H₂O· Ar_n (1 <= n <= 13) Clusters
S. A. Corcelli, J.A. Kelley, J. C. Tully, and M. A. Johnson, J. Phys. Chem. A, 106, 4872-4879, 2002. (Cover Article)

Linking the photoelectron and infrared spectroscopies of the (H₂O)₆^- isomers
J.A. Kelley, G. H. Weddle, W. H. Robertson, and M. A. Johnson, J. Chem. Phys., 116, 3, 1201-1203, 2002.

Solvation of the Cl^-· H₂O complex in CCl₄ clusters: The effect of solvent-mediated charge redistribution on the ionic H-bond
W. H. Robertson, G. H. Weddle, J. A. Kelley, and M. A. Johnson, J. Phys. Chem. A, 106, 1205-1209, 2002.

Argon predissociation and electron autodetachment spectra of size selected CH₃NO₂^-· Ar_n clusters
J.M. Weber, W.H. Robertson, and M.A. Johnson, J. Chem. Phys., 115, 10718-10723, 2001.

Observation of resonant two-photon photodetachment of water cluster anions via femtosecond photoelectron spectroscopy
J.M. Weber, J. Kim, E.A. Woronowicz, G.H. Weddle, I. Becker, O. Cheshnovsky and M.A. Johnson, Chem. Phys. Lett., 339, 337-342, 2001.

Hydration of a structured excess charge distribution: Infrared spectroscopy of the O₂^-· (H₂O)_n, (1 <= n <= 5) clusters
J. M. Weber, J. A. Kelley, W. H. Robertson, M. A. Johnson, J. Chem. Phys., 114, 6, 2698-2706, 2001.

A pulsed supersonic entrainment reactor for the rational preparation of cold ionic complexes
W. H. Robertson, J. A. Kelley, and M. A. Johnson, Rev. Sci. Instrum., 71, 4431-4434, 2000.

Dipole bound and valence state coupling in argon-solvated nitromethane anions
F. Lecomte, S. Carles, C. Desfrancois, and M. A. Johnson, J. Chem. Phys., 113, 10973-10977, 2000.

Double-contact ion-molecule binding: Infrared characterization of the ionic H-bonds to formic acid in the I^-· HCOOH complex
H. Robertson, J. A. Kelley, K. M. Lisle, and M. A. Johnson,  J. Chem. Phys., 113, 7879-7884, 2000.

The infrared predissociation spectra of CI^{- .} H₂O ^.Ar_n (n = 1-5):  Experimental determination of the influence of Ar_n
J. A. Kelley, J. M. Weber, K. M. Lisle, W. H. Robertson, P. Ayotte, and M. A. Johnson, Chem. Phys. Lett., 327, 1-6, 2000.

Infrared predissociation spectroscopy of the F^-· H₂O· Ar_n, (n = 1-3) complexes: Optically driven intracluster proton transfer?
Patrick Ayotte,  Jude A. Kelley, Steen B. Nielsen, and Mark A. Johnson, Chem. Phys. Lett., 316, 453-457, 2000.

Isolating the spectroscopic signature of a hydration shell using clusters:  Superoxide tetrahydrate
J. Mathias Weber, Jude A. Kelley, Steen B. Nielsen, Patrick Ayotte, and Mark A. Johnson, Science, 287, 2461, 2000.

Spectroscopic observation of vibrational Feshbach resonances in near-threshold photoexcitation of X^-· CH₃NO₂ (X^- = I^- and Br^- )
Caroline E. H. Dessent, Jun Kim and Mark A. Johnson, Faraday Discuss. 115, 395-406, 2000.

Infrared Spectra of Hydrogen-Bonded Ion-Radical Complexes: I^-· HCH₂ and Br^-· HCHBr
Steen B. Nielsen, Patrick Ayotte, Jude A. Kelley, Gary H. Weddle and Mark A. Johnson,  J. Chem. Phys., 111, 10464, 1999.

Infrared Spectroscopic Observation of the Argon Isomer Distribution in Evaporative Ensembles of I^-· ROH· Ar_m, (R = n methyl, ethyl, isopropyl) Clusters
Steen B. Nielsen, Patrick Ayotte, Jude A. Kelley and Mark A. Johnson, J. Chem. Phys., 111, 9593, 1999.

Spectroscopic observation of ion-induced water dimer dissociation in the X^-·(H₂O)₂, (X = F, Cl, Br, I) clusters
Patrick Ayotte, Steen B. Nielsen, Gary H. Weddle, and Mark A. Johnson, Sotiris S. Xantheas; Letter, J. Phys. Chem. A., 103, 10665-10669, 1999.

Photoactivation of the Cl^- + CH₃Br S_N2 reaction via rotationally resolved C-H stretch excitation of the Cl^-· CH₃Br entrance channel complex
Patrick Ayotte, Jun Kim, Jude A. Kelley, Steen B. Nielsen, and Mark A. Johnson,  J. Am. Chem. Soc. 121, 6950, 1999.

Preparation and photoelectron spectrum of the CH₃I^- anion:  Rare gas cluster mediated synthesis of an ion-radical complex
Jun Kim, Jude A. Kelley, Steen B. Nielsen, Patrick Ayotte, Gary H. Weddle, and Mark A. Johnson, Squires Issue of J. Am. Soc. Mass Spectrom. 10, 810, 1999.

An infrared study of the competition between hydrogen-bond networking and ionic solvation: Halide-dependent distortions of the water trimer in the X^-· (H₂O)₃, (X=Cl, Br, I) systems
Patrick Ayotte, Gary H. Weddle, and Mark A. Johnson, J. Chem. Phys. 110, 7129, 1999.

Infrared spectroscopy of negatively charged water clusters: Evidence for a linear network
Patrick Ayotte, Gary H. Weddle, Christopher G. Bailey, Mark A. Johnson, Fernando Vila, and Kenneth D. Jordan,  J. Chem. Phys. 110, 6268, 1999.

A cluster study of anionic hydration: Spectroscopic characterization of the I^-· W_n, 1 < n < 3, supramolecular complexes at the primary steps of solvation
Patrick Ayotte, Gary H. Weddle, Jun Kim, Jude A. Kelley, and Mark A. Johnson, J. Phys. Chem. A, 103, 443, 1999.

Electron Transfer and Charge Separation in Clusters
Israela Becker, Caroline E. H. Dessent, Mark A. Johnson, and Ori Cheshnovsky, Adv. Chem. Phys., 106, 265, 1999.

Fundamentals of Negative ion Photoelectron Spectroscopy
Caroline E. H. Dessent and Mark A. Johnson, NATO ASI on "Fundamentals and Applications of Gas Phase Ion Chemistry", Edited by K. R. Jennings, (Kluwer Academic Puslishers, the Netherlands), 1999.

Vibrational spectroscopy of the ionic hydrogen-bond: Fermi resonances and ion-molecule stretching frequencies in the binary X^-· H₂O (X = Cl, Br, I) complexes via argon predissociation spectroscopy
Patrick Ayotte, Gary H. Weddle, Jun Kim, and Mark A. Johnson, J. Am. Chem. Soc., 120, 12361, 1998.

Mass-selected "matrix isolation" infrared spectroscopy of the I^-· (H₂O)₂ complex: Making and breaking the inter-water hydrogen-bond
Patrick Ayotte, Gary H. Weddle, Jun Kim, and Mark A. Johnson, Chem. Phys., 239, 253, 1998.

Photoelectron spectroscopy of the "missing" hydrated electron clusters, (H₂O)_n^-, n = 3, 5, 8, and 9: Isomers and continuity with the dominant clusters n = 6, 7 and n > 11
Jun Kim, Israela Becker, Ori Cheshnovsky, and Mark A. Johnson, Chem. Phys. Lett., 297, 90, 1998.

Photochemistry of halide ion-molecule clusters: Dipole bound excited states and the case for asymmetric solvation
Caroline E. H. Dessent, Jun Kim, and Mark A. Johnson, Acc. Chem. Res. 31, 527, 1998.

Vibrational Spectroscopy of small Br^-· (H₂O)_n and I^-· (H₂O)_n clusters: Infrared Characterization of the Ionic Hydrogen Bond
Patrick Ayotte, Christopher G. Bailey, Gary H. Weddle, and Mark A. Johnson, J. Phys. Chem. A. 102, 3067, 1998.

Vibrational predissociation spectroscopy of the (H₂O)₆^-·Ar_n, n > 6 , clusters
Patrick Ayotte, Christopher G. Bailey, Jun Kim, and Mark Johnson, J. Chem. Phys. 108, 444, 1998.

Characterization of the anionic intracluster polymerization reaction product of 2-chloracrylonitrile trimers by photoelectron spectroscopy
T. Tsukuda, T. Kondow, C. E. H. Dessent, C. G. Bailey, M. A. Johnson, J. H. Hendricks, S. A. Lyapustina, and K. H. Bowen, Chem. Phys. Lett. 269, 17, 1997.

Photoinitiation of Gas-Phase S_N2 Reactions through the Evans-Polanyi Excited State Surface
Caroline E. H. Dessent and Mark Johnson, J. Am. Chem. Soc., 119, 5067, 1997.

Vibrational predissociation spectra of I^-· (H₂O): isotopic labels and weakly bound complexes with Ar and N_2.
Christopher G. Bailey, Jun Kim, Caroline E. H. Dessent, and Mark A. Johnson, Chem. Phys. Lett. 269, 122, 1997.

Photoelectron spectroscopy of (CO₂)_n^- revisited: core switching in the 2 < n < 16 range
Tatsuya Tsukuda, Mark A. Johnson, and Takashi Nagata, Chem. Phys. Lett. 268, 429, 1997.

Determination of the relative photodetachment cross sections of the two isomers of (H₂O)₆^- using saturated photodetachment
Christopher G. Bailey and Mark A. Johnson, Chem. Phys. Lett. 265, 185, 1997.

Electronic absorption spectra of size-selected hydrated electron clusters: (H₂O)_n^-, n = 6-50
Patrick Ayotte and Mark A. Johnson, J. Chem. Phys. 106, 811, 1997.

Evidence for asymmetric solvation in ion-molecule clusters from dipole-bound excited state spectroscopy
Caroline E. H. Dessent, Chris G. Bailey, Mark A. Johnson, in Structure and Dynamics of Clusters, edited by T. Kondow, K. Kaya, and A. Terasaki. (Universal Academy Press Inc., Tokyo, 1996) p. 329.

Infrared Spectroscopy of the Hydrated Electron Clusters (H₂O)_n^-, n= 6, 7: Evidence for Hydrogen Bonding to the Excess Electron
Chris G. Bailey, Jun Kim, and Mark A. Johnson, J. Phys. Chem. 100, 16782, 1996.

Vibronic effects in the photon energy-dependent photoelectron spectra of the CH₃CN^- dipole-bound anion
Christopher G. Bailey, Caroline E. H. Dessent, Mark A. Johnson, and Kit H. Bowen, Jr., J. Chem. Phys. 104, 6976, 1996.

Autodetachment from vibronic levels of the O₂^- A²P_u resonance across its dissociation limit by photoexcitation from O₂^- X²P_g
Christopher G. Bailey, David J. Lavrich, David Serxner, and Mark A. Johnson, J. Chem. Phys. 105, 1807, 1996.

Precursor of the I^-_aq charge-transfer-to-solvent (CTTS) band in the I^-· (H₂O)_n clusters
David Serxner, Caroline E. H. Dessent, and Mark A. Johnson, J. Chem. Phys., 105, 7231, 1996.

On the vibrational fine structure in the near-threshold photofragmentation spectrum of the I^-· CH₃I complex: Spectroscopic observation of nonadiabatic effects in electron-molecule scattering
Caroline E. H. Dessent, Christopher G. Bailey, and Mark A. Johnson, J. Chem. Phys. 105, 10416, 1996.

Evidence for the High-Energy (Collinear) Van der Waals Isomer of the Acetonitrile Dimer
Caroline E. H. Dessent, Jun Kim, and Mark A. Johnson,  J. Phys. Chem. 100, 12, 1996.

Thermal Energy Reactions of Size-Selected Hydrated Electron Clusters (H₂O)_n^-_.
Susan T. Arnold, Robert A. Morris, A. A. Viggiano, and Mark A. Johnson, J. Phys. Chem. 100, 2900, 1996.

Excess Energy-Dependent Photodissociation Probabilities for O₂^- in Water Clusters: O₂^-· (H₂O)_n, 1 < n < 33
David J. Lavrich, Mark A. Buntine, David Serxner, and Mark A. Johnson, J. Phys. Chem. 99, 8453, 1995.