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Yang N, Khuu T, Mitra S, Duong CH, Johnson MA, DiRisio RJ, McCoy AB, Miliordos E, Xantheas SS. Isolating the Contributions of Specific Network Sites to the Diffuse Vibrational Spectrum of Interfacial Water with Isotopomer-Selective Spectroscopy of Cold Clusters. J Phys Chem A 2020; 124:10393-10406. [PMID: 33270448 DOI: 10.1021/acs.jpca.0c07795] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Decoding the structural information contained in the interfacial vibrational spectrum of water requires understanding how the spectral signatures of individual water molecules respond to their local hydrogen bonding environments. In this study, we isolated the contributions for the five classes of sites that differ according to the number of donor (D) and acceptor (A) hydrogen bonds that characterize each site. These patterns were measured by exploiting the unique properties of the water cluster cage structures formed in the gas phase upon hydration of a series of cations M+·(H2O)n (M = Li, Na, Cs, NH4, CH3NH3, H3O, and n = 5, 20-22). This selection of ions was chosen to systematically express the A, AD, AAD, ADD, and AADD hydrogen bonding motifs. The spectral signatures of each site were measured using two-color, IR-IR isotopomer-selective photofragmentation vibrational spectroscopy of the cryogenically cooled, mass selected cluster ions in which a single intact H2O is introduced without isotopic scrambling, an important advantage afforded by the cluster regime. The resulting patterns provide an unprecedented picture of the intrinsic line shapes and spectral complexities associated with excitation of the individual OH groups, as well as the correlation between the frequencies of the two OH groups on the same water molecule, as a function of network site. The properties of the surrounding water network that govern this frequency map are evaluated by dissecting electronic structure calculations that explore how changes in the nearby network structures, both within and beyond the first hydration shell, affect the local frequency of an OH oscillator. The qualitative trends are recovered with a simple model that correlates the OH frequency with the network-modulated local electron density in the center of the OH bond.
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Affiliation(s)
- Nan Yang
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Thien Khuu
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Sayoni Mitra
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Chinh H Duong
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Mark A Johnson
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Ryan J DiRisio
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Evangelos Miliordos
- Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, Richland, Washington 99352, United States
| | - Sotiris S Xantheas
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States.,Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, Richland, Washington 99352, United States
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Talbot JJ, Yang N, Huang M, Duong CH, McCoy AB, Steele RP, Johnson MA. Spectroscopic Signatures of Mode-Dependent Tunnel Splitting in the Iodide-Water Binary Complex. J Phys Chem A 2020; 124:2991-3001. [PMID: 32162519 DOI: 10.1021/acs.jpca.0c00853] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The gas-phase vibrational spectrum of the isolated iodide-water cluster ion (I-·H2O), first reported in 1996, presents one of the most difficult, long-standing spectroscopic puzzles involving ion microhydration. Although the spectra of the smaller halides are well described in the context of an asymmetrical ground-state structure in which only one OH group is hydrogen-bonded to the ion, the I-·H2O spectrum displays multiplet structures with partially resolved rotational patterns that are additionally influenced by quantum nuclear spin statistics. In this study, this complex behavior is unraveled with a combination of experimental methods, including ion preparation in a temperature-controlled ion trap and spectral simplification through applications of tag-free, two-color IR-IR double-resonance spectroscopy. Analysis of the double-resonance spectra reveals a vibrational ground-state tunneling splitting of about 20 cm-1, which is on the same order as the spacing between the peaks that comprise the multiplet structure. These findings are further supported by the results obtained from a fully coupled, six-dimensional calculation of the vibrational spectrum. The underlying level structure can then be understood as a consequence of experimentally measurable, vibrational mode-dependent tunneling splittings (which, in the case of the ground vibrational state, is comparable to the rotational energy spacing between levels with Ka = 0 and 1), as well as Fermi resonance interactions. The latter include the hydrogen-bonded OH stretches and combination bands that involve the HOH bend overtones and soft-mode excitations of frustrated translation and rotation displacements of the water molecule relative to the ion. These anharmonic couplings yield closely spaced bands that are activated in the IR by borrowing intensity from the OH stretch fundamentals.
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Affiliation(s)
- Justin J Talbot
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Nan Yang
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Meng Huang
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Chinh H Duong
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Ryan P Steele
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Mark A Johnson
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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Mitra S, Duong CH, McCaslin LM, Gerber RB, Johnson MA. Isomer-specific cryogenic ion vibrational spectroscopy of the D 2 tagged Cs +(HNO 3)(H 2O) n=0-2 complexes: ion-driven enhancement of the acidic H-bond to water. Phys Chem Chem Phys 2020; 22:4501-4507. [PMID: 32068217 DOI: 10.1039/c9cp06689f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report how the binary HNO3(H2O) interaction is modified upon complexation with a nearby Cs+ ion. Isomer-selective IR photodissociation spectra of the D2-tagged, ternary Cs+(HNO3)H2O cation confirms that two structural isomers are generated in the cryogenic ion source. In one of these, both HNO3 and H2O are directly coordinated to the ion, while in the other, the water molecule is attached to the OH group of the acid, which in turn binds to Cs+ with its -NO2 group. The acidic OH stretching fundamental in the latter isomer displays a ∼300 cm-1 red-shift relative to that in the neutral H-bonded van der Waals complex, HNO3(H2O). This behavior is analyzed with the aid of electronic structure calculations and discussed in the context of the increased effective acidity of HNO3 in the presence of the cation.
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Affiliation(s)
- Sayoni Mitra
- Sterling Chemistry Laboratory, Yale University, New Haven, CT, USA.
| | - Chinh H Duong
- Sterling Chemistry Laboratory, Yale University, New Haven, CT, USA.
| | - Laura M McCaslin
- Department of Chemistry, University of California Irvine, Irvine, CA, USA. and Institute of Chemistry and the Fritz-Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem, Israel
| | - R Benny Gerber
- Department of Chemistry, University of California Irvine, Irvine, CA, USA. and Institute of Chemistry and the Fritz-Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem, Israel
| | - Mark A Johnson
- Sterling Chemistry Laboratory, Yale University, New Haven, CT, USA.
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Mitra S, Duong CH, McCaslin LM, Gerber RB, Johnson MA. Correction: Isomer-specific cryogenic ion vibrational spectroscopy of the D 2 tagged Cs +(HNO 3)(H 2O) n=0–2 complexes: ion-driven enhancement of the acidic H-bond to water. Phys Chem Chem Phys 2020; 22:6478. [DOI: 10.1039/d0cp90054k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for ‘Isomer-specific cryogenic ion vibrational spectroscopy of the D2 tagged Cs+(HNO3)(H2O)n=0–2 complexes: ion-driven enhancement of the acidic H-bond to water’ by Sayoni Mitra et al., Phys. Chem. Chem. Phys., 2020, DOI: 10.1039/c9cp06689f.
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Affiliation(s)
- Sayoni Mitra
- Sterling Chemistry Laboratory
- Yale University
- New Haven
- USA
| | - Chinh H. Duong
- Sterling Chemistry Laboratory
- Yale University
- New Haven
- USA
| | - Laura M. McCaslin
- Department of Chemistry
- University of California Irvine
- Irvine
- USA
- Institute of Chemistry and the Fritz-Haber Center for Molecular Dynamics
| | - R. Benny Gerber
- Department of Chemistry
- University of California Irvine
- Irvine
- USA
- Institute of Chemistry and the Fritz-Haber Center for Molecular Dynamics
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Duong CH, Yang N, Johnson MA, DiRisio RJ, McCoy AB, Yu Q, Bowman JM. Disentangling the Complex Vibrational Mechanics of the Protonated Water Trimer by Rational Control of Its Hydrogen Bonds. J Phys Chem A 2019; 123:7965-7972. [PMID: 31430153 DOI: 10.1021/acs.jpca.9b05576] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The vibrational spectrum of the protonated water trimer, H+(H2O)3, is surprisingly complex, with many strong features in the expected region of the fundamentals associated with two H-bonded OH groups on the H3O+ core ion. Here we follow how the bands in this region of the spectrum evolve when the energies of the fundamentals in the H-bonded OH stretches are systematically increased by the attachment of increasingly strongly bound "tag" molecules (He, Ar, D2, N2, CO, and H2O) to the free OH position on the hydronium core ion of H+(H2O)3, as well as by replacement of the hydrogen atom in the nonbonded OH group on hydronium with methyl and ethyl groups. This allows for the incremental transformation of the complex band pattern observed in H+(H2O)3 into that of the "Eigen" structure of the protonated water tetramer. Differences among the trajectories of the various bands provide an empirical way to disentangle features primarily due to the displacements of the OH stretches bound to the hydronium core from those arising from anharmonic coupling to states involving one or more quanta in lower frequency modes. The latter are found to be dramatically enhanced when the nominal frequencies of the intermolecular OH stretching modes approach those of the intramolecular bends of the H3O+ and H2O constituents in both H and D isotopologues.
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Affiliation(s)
- Chinh H Duong
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
| | - Nan Yang
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
| | - Mark A Johnson
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
| | - Ryan J DiRisio
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | - Anne B McCoy
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | - Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Computational Science , Emory University , Atlanta , Georgia 30322 , United States
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Computational Science , Emory University , Atlanta , Georgia 30322 , United States
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Menges FS, Perez EH, Edington SC, Duong CH, Yang N, Johnson MA. Integration of High-Resolution Mass Spectrometry with Cryogenic Ion Vibrational Spectroscopy. J Am Soc Mass Spectrom 2019; 30:1551-1557. [PMID: 31183838 PMCID: PMC6813835 DOI: 10.1007/s13361-019-02238-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 05/07/2023]
Abstract
We describe an instrumental configuration for the structural characterization of fragment ions generated by collisional dissociation of peptide ions in the typical MS2 scheme widely used for peptide sequencing. Structures are determined by comparing the vibrational band patterns displayed by cryogenically cooled ions with calculated spectra for candidate structural isomers. These spectra were obtained in a linear action mode by photodissociation of weakly bound D2 molecules. This is accomplished by interfacing a Thermo Fisher Scientific Orbitrap Velos Pro to a cryogenic, triple focusing time-of-flight photofragmentation mass spectrometer (the Yale TOF spectrometer). The interface involves replacement of the Orbitrap's higher-energy collisional dissociation cell with a voltage-gated aperture that maintains the commercial instrument's standard capabilities while enabling bidirectional transfer of ions between the high-resolution FT analyzer and external ion sources. The performance of this hybrid instrument is demonstrated by its application to the a1, y1 and z1 fragment ions generated by CID of a prototypical dipeptide precursor, protonated L-phenylalanyl-L-tyrosine (H+-Phe-Tyr-OH or FY-H+). The structure of the unusual z1 ion, nominally formed after NH3 is ejected from the protonated tyrosine (y1) product, is identified as the cyclopropane-based product is tentatively identified as a cyclopropane-based product.
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Affiliation(s)
- Fabian S Menges
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Evan H Perez
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Sean C Edington
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Chinh H Duong
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Nan Yang
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Mark A Johnson
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA.
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Yang N, Duong CH, Kelleher PJ, McCoy AB, Johnson MA. Deconstructing water's diffuse OH stretching vibrational spectrum with cold clusters. Science 2019; 364:275-278. [PMID: 31000660 DOI: 10.1126/science.aaw4086] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/11/2019] [Indexed: 05/05/2023]
Abstract
The diffuse vibrational envelope displayed by water precludes direct observation of how different hydrogen-bond topologies dictate the spectral response of individual hydroxy group (OH) oscillators. Using cold, isotopically labeled cluster ions, we report the spectral signatures of a single, intact water (H2O) molecule embedded at various sites in the clathrate-like cage structure adopted by the Cs+·(D2O)20 ion. These patterns reveal the site-dependent correlation between the frequencies of the two OH groups on the same water molecule and establish that the bound OH companion of the free OH group exclusively accounts for bands in the lower-energy region of the spectrum. The observed multiplet structures reveal the homogeneous linewidths of the fundamentals and quantify the anharmonic contributions arising from coupling to both the intramolecular bending and intermolecular soft modes.
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Affiliation(s)
- Nan Yang
- Sterling Chemistry Laboratory, Yale University, New Haven, CT 06520, USA
| | - Chinh H Duong
- Sterling Chemistry Laboratory, Yale University, New Haven, CT 06520, USA
| | - Patrick J Kelleher
- Sterling Chemistry Laboratory, Yale University, New Haven, CT 06520, USA
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
| | - Mark A Johnson
- Sterling Chemistry Laboratory, Yale University, New Haven, CT 06520, USA.
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Duong CH, Yang N, Kelleher PJ, Johnson MA, DiRisio RJ, McCoy AB, Yu Q, Bowman JM, Henderson BV, Jordan KD. Tag-Free and Isotopomer-Selective Vibrational Spectroscopy of the Cryogenically Cooled H9O4+ Cation with Two-Color, IR–IR Double-Resonance Photoexcitation: Isolating the Spectral Signature of a Single OH Group in the Hydronium Ion Core. J Phys Chem A 2018; 122:9275-9284. [DOI: 10.1021/acs.jpca.8b08507] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Chinh H. Duong
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Nan Yang
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Patrick J. Kelleher
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Mark A. Johnson
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Ryan J. DiRisio
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Anne B. McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Computational Science, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Department of Chemistry and Cherry L. Emerson Center for Computational Science, Emory University, Atlanta, Georgia 30322, United States
| | - Bryan V. Henderson
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Kenneth D. Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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Spieler S, Duong CH, Kaiser A, Duensing F, Geistlinger K, Fischer M, Yang N, Kumar SS, Johnson MA, Wester R. Vibrational Predissociation Spectroscopy of Cold Protonated Tryptophan with Different Messenger Tags. J Phys Chem A 2018; 122:8037-8046. [PMID: 30208709 DOI: 10.1021/acs.jpca.8b07532] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Vibrational spectra of protonated tryptophan were recorded by predissociation of H2 messenger tags using cryogenic ion traps. We explore the issue of messenger induced spectral changes by solvating TrpH+(H2) n with n = 1-5 to obtain single photon vibrational spectra of TrpH+ and of its partly deuterated isotopomer in the spectral region of 800-4400 cm-1. Depending on the number of messenger molecules, the spectra of several conformational isomers associated with multiple H2 binding locations along with two natural conformations of TrpH+ were found using the two photon MS3IR2 conformational hole burning method. Most probable messenger positions were established by comparison with predictions from DFT calculations on various candidate structures. Mechanical anharmonicity effects associated with the charged amino group were modeled by Born-Oppenheimer ab initio molecular dynamics. The spectra of TrpH+(H2O) m=1,2, recorded by infrared multiphoton dissociation (IRMPD), reveal broad features in the NH stretching region of the NH3+ group, indicating strong hydrogen bonding in acceptor-donor configuration with the benzene ring for the first water molecule, while the second water appears to attach to a less strongly perturbing site, yielding unique transitions associated with the free OH stretching fundamentals. We discuss the structural deformations induced by the water molecules and compare our results to recent experiments on similar hydrated cationic systems.
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Affiliation(s)
- Steffen Spieler
- Institut für Ionenphysik und Angewandte Physik , Universität Innsbruck , Technikerstraße 25 , 6020 Innsbruck , Austria
| | - Chinh H Duong
- Sterling Chemistry Laboratory , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States
| | - Alexander Kaiser
- Institut für Ionenphysik und Angewandte Physik , Universität Innsbruck , Technikerstraße 25 , 6020 Innsbruck , Austria
| | - Felix Duensing
- Institut für Ionenphysik und Angewandte Physik , Universität Innsbruck , Technikerstraße 25 , 6020 Innsbruck , Austria
| | - Katharina Geistlinger
- Institut für Ionenphysik und Angewandte Physik , Universität Innsbruck , Technikerstraße 25 , 6020 Innsbruck , Austria
| | - Moritz Fischer
- Institut für Ionenphysik und Angewandte Physik , Universität Innsbruck , Technikerstraße 25 , 6020 Innsbruck , Austria
| | - Nan Yang
- Sterling Chemistry Laboratory , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States
| | - S Sunil Kumar
- Department of Physics , Indian Institute of Science Education and Research , Tirupati, Rami Reddy Nagar, Karakambadi Road , Mangalam (P.O.) Tirupati 517507 , Andhra Pradesh , India
| | - Mark A Johnson
- Sterling Chemistry Laboratory , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States
| | - Roland Wester
- Institut für Ionenphysik und Angewandte Physik , Universität Innsbruck , Technikerstraße 25 , 6020 Innsbruck , Austria
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Yang N, Duong CH, Kelleher PJ, Johnson MA. Unmasking Rare, Large-Amplitude Motions in D 2-Tagged I -·(H 2O) 2 Isotopomers with Two-Color, Infrared-Infrared Vibrational Predissociation Spectroscopy. J Phys Chem Lett 2018; 9:3744-3750. [PMID: 29924622 DOI: 10.1021/acs.jpclett.8b01485] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We describe a two-color, isotopomer-selective infrared-infrared population-labeling method that can monitor very slow spectral diffusion of OH oscillators in H-bonded networks and apply it to the I-·(HDO)·(D2O) and I-·(H2O)·(D2O) systems, which are cryogenically cooled and D2-tagged at an ion trap temperature of 15 K. These measurements reveal very large (>400 cm-1), spontaneous spectral shifts despite the fact that the predissociation spectra in the OH stretching region of both isotopologues are sharp and readily assigned to four fundamentals of largely decoupled OH oscillators held in a cyclic H-bonded network. This spectral diffusion is not observed in the untagged isotopologues of the dihydrate clusters that are generated under the same source conditions but does become apparent at about 75 K. These results are discussed in the context of the large-amplitude "jump" mechanism for H-bond relaxation dynamics advanced by Laage and Hynes in an experimental scenario where rare events can be captured by following the migration of OH groups among the four available positions in the quasi-rigid equilibrium structure.
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Affiliation(s)
- Nan Yang
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
| | - Chinh H Duong
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
| | - Patrick J Kelleher
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
| | - Mark A Johnson
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
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Yang N, Duong CH, Kelleher PJ, Johnson MA, McCoy AB. Isolation of site-specific anharmonicities of individual water molecules in the I−·(H2O)2 complex using tag-free, isotopomer selective IR-IR double resonance. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.09.042] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Duong CH, Gorlova O, Yang N, Kelleher PJ, Johnson MA, McCoy AB, Yu Q, Bowman JM. Disentangling the Complex Vibrational Spectrum of the Protonated Water Trimer, H +(H 2O) 3, with Two-Color IR-IR Photodissociation of the Bare Ion and Anharmonic VSCF/VCI Theory. J Phys Chem Lett 2017; 8:3782-3789. [PMID: 28737922 DOI: 10.1021/acs.jpclett.7b01599] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Vibrational spectroscopy of the protonated water trimer provides a stringent constraint on the details of the potential energy surface (PES) and vibrational dynamics governing excess proton motion far from equilibrium. Here we report the linear spectrum of the cold, bare H+(H2O)3 ion using a two-color, IR-IR photofragmentation technique and follow the evolution of the bands with increasing ion trap temperature. The key low-energy features are insensitive to both D2 tagging and internal energy. The D2-tagged D+(D2O)3 spectrum is reported for the first time, and the isotope dependence of the band pattern is surprisingly complex. These spectra are reproduced by large-scale vibrational configuration interaction calculations based on a new full-dimensional PES, which treat the anharmonic effects arising from large amplitude motion. The results indicate such extensive mode mixing in both isotopologues that one should be cautious about assigning even the strongest features to particular motions, especially for the absorptions that occur close to the intramolecular bending mode of the water molecule.
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Affiliation(s)
- Chinh H Duong
- Sterling Chemistry Laboratory, Yale University , New Haven, Connecticut 06520, United States
| | - Olga Gorlova
- Sterling Chemistry Laboratory, Yale University , New Haven, Connecticut 06520, United States
| | - Nan Yang
- Sterling Chemistry Laboratory, Yale University , New Haven, Connecticut 06520, United States
| | - Patrick J Kelleher
- Sterling Chemistry Laboratory, Yale University , New Haven, Connecticut 06520, United States
| | - Mark A Johnson
- Sterling Chemistry Laboratory, Yale University , New Haven, Connecticut 06520, United States
| | - Anne B McCoy
- Department of Chemistry, University of Washington , Seattle, Washington 98195, United States
| | - Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Computational Science, Emory University , Atlanta, Georgia 30322, United States
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Computational Science, Emory University , Atlanta, Georgia 30322, United States
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