1
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Huang QR, Yano K, Yang Y, Fujii A, Kuo JL. Near-infrared spectroscopy of H 3O +⋯X n (X = Ar, N 2, and CO, n = 1-3). Phys Chem Chem Phys 2024; 26:10757-10768. [PMID: 38516880 DOI: 10.1039/d4cp00458b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Near-infrared (NIR) spectra of H3O+⋯Xn (X = Ar, N2, and CO, n = 1-3) in the first overtone region of OH-stretching vibrations (4800-7000 cm-1) were measured. Not only OH-stretching overtones but also several combination bands are major features in this region, and assignments of these observed bands are not obvious at a glance. High-precision anharmonic vibrational simulations based on the discrete variable representation approach were performed. The simulated spectra show good agreement with the observed ones and provide firm assignments of the observed bands, except in the case of X = CO, in which higher order vibrational mode couplings seem significant. This agreement demonstrates that the present system can be a benchmark for high precision anharmonic vibrational computations of NIR spectra. Band broadening in the observed spectra becomes remarkable with an increase of the interaction with the solvent molecule (X). The origin of the band broadening is explored by rare gas tagging experiments and anharmonic vibrational simulations of hot bands.
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Affiliation(s)
- Qian-Rui Huang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan.
| | - Kazuyoshi Yano
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan.
| | - Yaodi Yang
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan.
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan.
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan.
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2
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Zhang Y, Wang Y, Xu X, Chen Z, Yang Y. Vibrational Spectra of Highly Anharmonic Water Clusters: Molecular Dynamics and Harmonic Analysis Revisited with Constrained Nuclear-Electronic Orbital Methods. J Chem Theory Comput 2023; 19:9358-9368. [PMID: 38096546 DOI: 10.1021/acs.jctc.3c01037] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Vibrational spectroscopy is widely used to gain insights into structural and dynamic properties of chemical, biological, and materials systems. Thus, an efficient and accurate method to simulate vibrational spectra is desired. In this paper, we justify and employ a microcanonical molecular simulation scheme to calculate the vibrational spectra of three challenging water clusters: the neutral water dimer (H4O2), the protonated water trimer (H7O3+), and the protonated water tetramer (H9O4+). We find that with the accurate description of quantum nuclear delocalization effects through the constrained nuclear-electronic orbital framework, including vibrational mode coupling effects through molecular dynamics simulations can additionally improve the vibrational spectrum calculations. In contrast, without the quantum nuclear delocalization picture, conventional ab initio molecular dynamics may even lead to less accurate results than harmonic analysis.
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Affiliation(s)
- Yuzhe Zhang
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Yiwen Wang
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Xi Xu
- Center for Advanced Materials Research, Beijing Normal University, Zhuhai 519087, China
| | - Zehua Chen
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Yang Yang
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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3
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The coupling of the hydrated proton to its first solvation shell. Nat Commun 2022; 13:6170. [PMID: 36257946 PMCID: PMC9579203 DOI: 10.1038/s41467-022-33650-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 09/28/2022] [Indexed: 11/30/2022] Open
Abstract
The Zundel (\documentclass[12pt]{minimal}
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\begin{document}$${H}_{5}{O}_{2}^{+}$$\end{document}H5O2+) and Eigen (\documentclass[12pt]{minimal}
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\begin{document}$${H}_{9}{O}_{4}^{+}$$\end{document}H9O4+) cations play an important role as intermediate structures for proton transfer processes in liquid water. In the gas phase they exhibit radically different infrared (IR) spectra. The question arises: is there a least common denominator structure that explains the IR spectra of both, the Zundel and Eigen cations, and hence of the solvated proton? Full dimensional quantum simulations of these protonated cations demonstrate that two dynamical water molecules and an excess proton constitute this fundamental subunit. Embedded in the static environment of the parent Eigen cation, this subunit reproduces the positions and broadenings of its main excess-proton bands. In isolation, its spectrum reverts to the well-known Zundel ion. Hence, the dynamics of this subunit polarized by an environment suffice to explain the spectral signatures and anharmonic couplings of the solvated proton in its first solvation shell. The Zundel [H(H2O)2]+ and Eigen [H(H2O)4]+ cations exhibit radicallly different infrared spectra and are the limiting dynamical structures involved in proton mobility in liquid water. Here, the authors find through quantum dynamics simulations that two polarized water molecules and a proton suffice to explain the key spectroscopic features connected to proton mobility for both species.
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4
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DiRisio RJ, Finney JM, McCoy AB. Diffusion Monte Carlo approaches for studying nuclear quantum effects in fluxional molecules. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2022. [DOI: 10.1002/wcms.1615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ryan J. DiRisio
- Department of Chemistry University of Washington Seattle Washington USA
| | - Jacob M. Finney
- Department of Chemistry University of Washington Seattle Washington USA
| | - Anne B. McCoy
- Department of Chemistry University of Washington Seattle Washington USA
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5
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Mitra S, Khuu T, Choi TH, Huchmala RM, Jordan KD, McCoy AB, Johnson MA. Vibrational Signatures of HNO 3 Acidity When Complexed with Microhydrated Alkali Metal Ions, M +·(HNO 3)(H 2O) n=5 (M = Li, K, Na, Rb, Cs), at 20 K. J Phys Chem A 2022; 126:1640-1647. [PMID: 35249322 DOI: 10.1021/acs.jpca.1c10352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The speciation of strong acids like HNO3 under conditions of restricted hydration is an important factor in the rates of chemical reactions at the air-water interface. Here, we explore the trade-offs at play when HNO3 is attached to alkali ions (Li+-Cs+) with four water molecules in their primary hydration shells. This is achieved by analyzing the vibrational spectra of the M+·(HNO3)(H2O)5 clusters cooled to about 20 K in a cryogenic photofragmentation mass spectrometer. The local acidity of the acidic OH group is estimated by the extent of the red shift in its stretching frequency when attached to a single water molecule. The persistence of this local structural motif (HNO3-H2O) in all of these alkali metal clusters enables us to determine the competition between the effect of the direct complexation of the acid with the cation, which acts to enhance acidity, and the role of the water network in the first hydration shell around the ions, which acts to counter (screen) the intrinsic effect of the ion. Analysis of the vibrational features associated with the acid molecule, as well as those of the water network, reveals how cooperative interactions in the microhydration regime conspire to effectively offset the intrinsic enhancement of HNO3 acidity afforded by attachment to the smaller cations.
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Affiliation(s)
- Sayoni Mitra
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Thien Khuu
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Tae Hoon Choi
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Rachel M Huchmala
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Kenneth D Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Mark A Johnson
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
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6
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Huchmala RM, McCoy AB. Exploring the Origins of Spectral Signatures of Strong Hydrogen Bonding in Protonated Water Clusters. J Phys Chem A 2022; 126:1360-1368. [PMID: 35171593 DOI: 10.1021/acs.jpca.1c10036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effects of anharmonicity on the spectral features of strong ionic hydrogen bonds are explored through reduced dimensional studies of the couplings between the hydrogen bonding OH and the donor-acceptor OO stretching vibrations in protonated water clusters with 2-4 water molecules. Specifically, this study focuses on how the anharmonicities and couplings in these ions are reflected in the vibrational spectra by exploring the intensities of the transitions to states with excitation in both the OH and the OO stretching vibrations and changes in the frequency of the OO stretching vibration when the OH stretching vibration is excited. These questions are addressed through the application of several approximate treatments that are based on an adiabatic separation of the high-frequency OH and low-frequency OO stretching vibrations as well as low-order expansions of the potential and dipole surfaces. While an adiabatic approximation captures most of the trends found in the spectra and from an analysis of the two-dimensional model, a vibrational Franck-Condon approach fails to capture the intensities of these transitions. Of the terms in the expansion of the dipole moment function, those that are proportional to ΔrOH and ΔrOH2 are found to provide the largest contributions to the calculated intensities of the transitions involving excitation of both the OH and the OO stretches. This leads to the conclusion that the intensities of these transitions encode information about the frequency and anharmonicity of the OH stretching vibration and how they are affected by changes in the OO distance. The anharmonicity of the potential also leads to changes in the OO stretching frequency with excitation of the OH stretching vibration. The direction of this change in frequency encodes additional information about the strength of the ionic hydrogen bond.
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Affiliation(s)
- Rachel M Huchmala
- 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
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7
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Thomas DA, Taccone M, Ober K, Mucha E, Meijer G, von Helden G. Helium Nanodroplet Infrared Action Spectroscopy of the Proton-Bound Dimer of Hydrogen Sulfate and Formate: Examining Nuclear Quantum Effects. J Phys Chem A 2021; 125:9279-9287. [PMID: 34652165 PMCID: PMC8558860 DOI: 10.1021/acs.jpca.1c05705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The proton-bound dimer of hydrogen sulfate and formate is an archetypal structure for ionic hydrogen-bonding complexes that contribute to biogenic aerosol nucleation. Of central importance for the structure and properties of this complex is the location of the bridging proton connecting the two conjugate base moieties. The potential energy surface for bridging proton translocation features two local minima, with the proton localized at either the formate or hydrogen sulfate moiety. However, electronic structure methods reveal a shallow potential energy surface governing proton translocation, with a barrier on the order of the zero-point energy. This shallow potential complicates structural assignment and necessitates a consideration of nuclear quantum effects. In this work, we probe the structure of this complex and its isotopologues, utilizing infrared (IR) action spectroscopy of ions captured in helium nanodroplets. The IR spectra indicate a structure in which a proton is shared between the hydrogen sulfate and formate moieties, HSO4-···H+···-OOCH. However, because of the nuclear quantum effects and vibrational anharmonicities associated with the shallow potential for proton translocation, the extent of proton displacement from the formate moiety remains unclear, requiring further experiments or more advanced theoretical treatments for additional insight.
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Affiliation(s)
- Daniel A Thomas
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Martín Taccone
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Katja Ober
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Eike Mucha
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Gerard Meijer
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Gert von Helden
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
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8
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Chen L, Fournier JA. Probing Hydrogen-Bonding Interactions within Phenol-Benzimidazole Proton-Coupled Electron Transfer Model Complexes with Cryogenic Ion Vibrational Spectroscopy. J Phys Chem A 2021; 125:9288-9297. [PMID: 34652915 DOI: 10.1021/acs.jpca.1c05879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hydrogen-bonding interactions within a series of phenol-benzimidazole model proton-coupled electron transfer (PCET) dyad complexes are characterized using cryogenic ion vibrational spectroscopy. A highly red-shifted and surprisingly broad (>1000 cm-1) transition is observed in one of the models and assigned to the phenolic OH stretch strongly H-bonded to the N(3) benzimidazole atom. The breadth is attributed to a combination of anharmonic Fermi-resonance coupling between the OH stretch and background doorway states involving OH bending modes and strong coupling of the OH stretch frequency to structural deformations along the proton-transfer coordinate accessible at the vibrational zero-point level. The other models show unexpected protonation of the benzimidazole group upon electrospray ionization instead of at more basic remote amine/amide groups. This leads to the formation of HO-+HN(3) H-bond motifs that are much weaker than the OH-N(3) H-bond arrangement. H-bonding between the N(1)H+ benzimidazole group and the carbonyl on the tyrosine backbone is the stronger and preferred interaction in these complexes. The results show that conjugation effects, secondary H-bond interactions, and H-bond soft modes strongly influence the OH-N(3) interaction and highlight the importance of the direct monitoring of proton stretch transitions in characterizing the proton-transfer reaction coordinate in PCET systems.
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Affiliation(s)
- Liangyi Chen
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Joseph A Fournier
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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9
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Harrilal CP, DeBlase AF, McLuckey SA, Zwier TS. Two-Color IRMPD Applied to Conformationally Complex Ions: Probing Cold Ion Structure and Hot Ion Unfolding. J Phys Chem A 2021; 125:9394-9404. [PMID: 34644093 DOI: 10.1021/acs.jpca.1c08388] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Two-color infrared multiphoton dissociation (2C-IRMPD) spectroscopy is a technique that mitigates spectral distortions due to nonlinear absorption that is inherent to one-color IRMPD. We use a 2C-IRMPD scheme that incorporates two independently tunable IR sources, providing considerable control over the internal energy content and type of spectrum obtained by varying the trap temperature, the time delays and fluences of the two infrared lasers, and whether the first or second laser wavelength is scanned. In this work, we describe the application of this variant of 2C-IRMPD to conformationally complex peptide ions. The 2C-IRMPD technique is used to record near-linear action spectra of both cations and anions with temperatures ranging from 10 to 300 K. We also determine the conditions under which it is possible to record IR spectra of single conformers in a conformational mixture. Furthermore, we demonstrate the capability of the technique to explore conformational unfolding by recording IR spectra with widely varying internal energy in the ion. The protonated peptide ions YGGFL (NH3+-Tyr-Gly-Gly-Phe-Leu, Leu-enkephalin) and YGPAA (NH3+-Tyr-Gly-Pro-Ala-Ala) are used as model systems for exploring the advantages and disadvantages of the method when applied to conformationally complex ions.
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Affiliation(s)
- Christopher P Harrilal
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Andrew F DeBlase
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Scott A McLuckey
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Timothy S Zwier
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States.,Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, United States
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10
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Hanson MD, Readnour JA, Hassanali AA, Corcelli SA. Coupled Local-Mode Approach for the Calculation of Vibrational Spectra: Application to Protonated Water Clusters. J Phys Chem Lett 2021; 12:9226-9232. [PMID: 34529914 DOI: 10.1021/acs.jpclett.1c02254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Spectroscopic studies of protonated water clusters (PWCs) have yielded enormous insights into the fundamental nature of the hydrated proton. Here, we introduce a new coupled local-mode (CLM) approach to calculate PWC OH stretch vibrational spectra. The CLM method combines a sampling of representative configurations from density functional theory (DFT)-based ab initio molecular dynamics (AIMD) simulations with DFT calculations of local-mode vibrational frequencies and couplings. Calculations of inhomogeneous OH stretch vibrational spectra for H+(H2O)4 and H+(H2O)21 agree well with experiment and higher-level calculations, and decompositions of the calculated spectra in terms of the coupled modes aids in the interpretation of the spectra. This observation is consistent with the idea that capturing anharmonicity and coupling is as important to accuracy as the underlying level of electronic structure theory. The CLM calculations can easily discern the configuration that dominates the experimental measurement for H+(H2O)5, which can adopt several low-energy conformations.
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Affiliation(s)
- Matthew D Hanson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Janel A Readnour
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Ali A Hassanali
- Condensed Matter and Statistical Physics, International Centre for Theoretical Physics, Strada Costiera, 11 I - 34151 Trieste, Italy
| | - Steven A Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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11
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Inakollu VSS, Yu H. Comparative studies of IR spectra of deprotonated serine with classical and thermostated ring polymer molecular dynamics simulations. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:054101. [PMID: 34549074 PMCID: PMC8443303 DOI: 10.1063/4.0000124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/30/2021] [Indexed: 06/13/2023]
Abstract
Here we report the vibrational spectra of deprotonated serine calculated from the classical molecular dynamics (MD) simulations and thermostated ring-polymer molecular dynamics (TRPMD) simulation with third-order density-functional tight-binding. In our earlier study [Inakollu and Yu, "A systematic benchmarking of computational vibrational spectroscopy with DFTB3: Normal mode analysis and fast Fourier transform dipole autocorrelation function," J. Comput. Chem. 39, 2067 (2018)] of deprotonated serine, we observed a significant difference in the vibrational spectra with the classical MD simulations compared to the infrared multiple photon dissociation spectra. It was postulated that this is due to neglecting the nuclear quantum effects (NQEs). In this work, NQEs are considered in spectral calculation using the TRPMD simulations. With the help of potential of mean force calculations, the conformational space of deprotonated serine is analyzed and used to understand the difference in the spectra of classical MD and TRPMD simulations at 298.15 and 100 K. The high-frequency vibrational bands in the spectra are characterized using Fourier transform localized vibrational mode (FT-νN AC) and interatomic distance histograms. At room temperature, the quantum effects are less significant, and the free energy profiles in the classical MD and the TRPMD simulations are very similar. However, the hydrogen bond between the hydroxyl-carboxyl bond is slightly stronger in TRPMD simulations. At 100 K, the quantum effects are more prominent, especially in the 2600-3600 cm-1, and the free energy profile slightly differs between the classical MD and TRPMD simulations. Using the FT-νN AC and the interatomic distance histograms, the high-frequency vibrational bands are discussed in detail.
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Affiliation(s)
| | - Haibo Yu
- Author to whom correspondence should be addressed:
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12
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DiRisio RJ, Finney JM, Dzugan LC, Madison LR, McCoy AB. Using Diffusion Monte Carlo Wave Functions to Analyze the Vibrational Spectra of H 7O 3+ and H 9O 4. J Phys Chem A 2021; 125:7185-7197. [PMID: 34433268 DOI: 10.1021/acs.jpca.1c05025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An approach for evaluating spectra from ground state probability amplitudes (GSPA) obtained from diffusion Monte Carlo (DMC) simulations is extended to improve the description of excited state energies and allow for coupling among vibrational excited states. This approach is applied to studies of the protonated water trimer and tetramer, and their deuterated analogs. These ions provide models for solvated hydronium, and analysis of these spectra provides insights into spectral signatures of proton transfer in aqueous environments. In this approach, we obtain a separable set of internal coordinates from the DMC ground state probability amplitude. A basis is then developed from products of the DMC ground state wave function and low-order polynomials in these internal coordinates. This approach provides a compact basis in which the Hamiltonian and dipole moment matrix are evaluated and used to obtain the spectrum. The resulting spectra are in good agreement with experiment and in many cases provide comparable agreement to the results obtained using much larger basis sets. In addition, the compact basis allows for interpretation of the spectral features and how they evolve with cluster size and deuteration.
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Affiliation(s)
- Ryan J DiRisio
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Jacob M Finney
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Laura C Dzugan
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Lindsey R Madison
- Department of Chemistry, Colby College, Waterville, Maine 04901, United States
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
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13
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Altman RM, Richmond GL. Twist and Stretch: Assignment and Surface Charge Sensitivity of a Water Combination Band and Its Implications for Vibrational Sum Frequency Spectra Interpretations. J Phys Chem B 2021; 125:6717-6726. [DOI: 10.1021/acs.jpcb.1c03408] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Rebecca M. Altman
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
| | - Geraldine L. Richmond
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
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14
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Zeng HJ, Johnson MA. Demystifying the Diffuse Vibrational Spectrum of Aqueous Protons Through Cold Cluster Spectroscopy. Annu Rev Phys Chem 2021; 72:667-691. [PMID: 33646816 DOI: 10.1146/annurev-physchem-061020-053456] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ease with which the pH is routinely determined for aqueous solutions masks the fact that the cationic product of Arrhenius acid dissolution, the hydrated proton, or H+(aq), is a remarkably complex species. Here, we review how results obtained over the past 30 years in the study of H+⋅(H2O)n cluster ions isolated in the gas phase shed light on the chemical nature of H+(aq). This effort has also revealed molecular-level aspects of the Grotthuss relay mechanism for positive-charge translocation in water. Recently developed methods involving cryogenic cooling in radiofrequency ion traps and the application of two-color, infrared-infrared (IR-IR) double-resonance spectroscopy have established a clear picture of how local hydrogen-bond topology drives the diverse spectral signatures of the excess proton. This information now enables a new generation of cluster studies designed to unravel the microscopic mechanics underlying the ultrafast relaxation dynamics displayed by H+(aq).
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Affiliation(s)
- Helen J Zeng
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, USA;
| | - Mark A Johnson
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, USA;
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15
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Zeng HJ, Khuu T, Chambreau SD, Boatz JA, Vaghjiani GL, Johnson MA. Ionic Liquid Clusters Generated from Electrospray Thrusters: Cold Ion Spectroscopic Signatures of Size-Dependent Acid-Base Interactions. J Phys Chem A 2020; 124:10507-10516. [PMID: 33284621 DOI: 10.1021/acs.jpca.0c07595] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We determine the intramolecular distortions at play in the 2-hydroxyethylhydrazinium nitrate (HEHN) ionic liquid (IL) propellant, which presents the interesting case that the HEH+ cation has multiple sites (i.e., hydroxy, primary amine, and secondary ammonium groups) available for H-bonding with the nitrate anion. These interactions are quantified by analyzing the vibrational band patterns displayed by cold cationic clusters, (HEH+)n(NO3-)n-1, n = 2-6, which are obtained using IR photodissociation of the cryogenically cooled, mass-selected ions. The strong interaction involving partial proton transfer of the acidic N-H proton in HEH+ cation to the nitrate anion is strongly enhanced in the ternary n = 2 cluster but is suppressed with increasing cluster size. The cluster spectra recover the bands displayed by the bulk liquid by n = 5, thus establishing the minimum domain required to capture this aspect of macroscopic behavior.
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Affiliation(s)
- Helen J Zeng
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Thien Khuu
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
| | - Steven D Chambreau
- Jacobs Technology, Inc., Air Force Research Laboratory, AFRL/RQRP, Edwards Air Force Base, California 93524, United States
| | - Jerry A Boatz
- Propellants Branch, Rocket Propulsion Division, Aerospace Systems Directorate, Air Force Research Laboratory, AFRL/RQRP, Edwards Air Force Base, California 93524, United States
| | - Ghanshyam L Vaghjiani
- In-Space Propulsion Branch, Rocket Propulsion Division, Aerospace Systems Directorate, Air Force Research Laboratory, AFRL/RQRP, Edwards Air Force Base, California 93524, United States
| | - Mark A Johnson
- Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States
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16
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Aarøen O, Kiær H, Riccardi E. PyVisA
: Visualization and Analysis of path sampling trajectories. J Comput Chem 2020; 42:435-446. [DOI: 10.1002/jcc.26467] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/03/2020] [Accepted: 11/26/2020] [Indexed: 12/20/2022]
Affiliation(s)
- Ola Aarøen
- Department of Biotechnology and Food Science Norwegian University of Science and Technology Trondheim Norway
| | - Henrik Kiær
- Department of Chemistry Norwegian University of Science and Technology Trondheim Norway
| | - Enrico Riccardi
- Department of Chemistry Norwegian University of Science and Technology Trondheim Norway
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17
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Sofronov OO, Bakker HJ. Nature of hydrated proton vibrations revealed by nonlinear spectroscopy of acid water nanodroplets. Phys Chem Chem Phys 2020; 22:21334-21339. [PMID: 32936152 DOI: 10.1039/d0cp03137b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We use polarization-resolved femtosecond pump-probe spectroscopy to investigate the vibrations of hydrated protons in anionic (AOT) and cationic (CTAB/hexanol) reverse micelles in the frequency range 2000-3500 cm-1. For small AOT micelles the dominant proton hydration structure consists of H3O+ with two OH groups donating hydrogen bonds to water molecules, and one OH group donating a weaker hydrogen bond to sulfonate. For cationic reverse micelles, we find that the absorption at frequencies >2500 cm-1 is dominated by asymmetric proton-hydration structures in which one of the OH groups of H3O+ is more weakly hydrogen-bonded to water than the other two OH groups.
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18
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Carpenter WB, Yu Q, Hack JH, Dereka B, Bowman JM, Tokmakoff A. Decoding the 2D IR spectrum of the aqueous proton with high-level VSCF/VCI calculations. J Chem Phys 2020; 153:124506. [PMID: 33003749 DOI: 10.1063/5.0020279] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The aqueous proton is a common and long-studied species in chemistry, yet there is currently intense interest devoted to understanding its hydration structure and transport dynamics. Typically described in terms of two limiting structures observed in gas-phase clusters, the Zundel H5O2 + and Eigen H9O4 + ions, the aqueous structure is less clear due to the heterogeneity of hydrogen bonding environments and room-temperature structural fluctuations in water. The linear infrared (IR) spectrum, which reports on structural configurations, is challenging to interpret because it appears as a continuum of absorption, and the underlying vibrational modes are strongly anharmonically coupled to each other. Recent two-dimensional IR (2D IR) experiments presented strong evidence for asymmetric Zundel-like motifs in solution, but true structure-spectrum correlations are missing and complicated by the anharmonicity of the system. In this study, we employ high-level vibrational self-consistent field/virtual state configuration interaction calculations to demonstrate that the 2D IR spectrum reports on a broad distribution of geometric configurations of the aqueous proton. We find that the diagonal 2D IR spectrum around 1200 cm-1 is dominated by the proton stretch vibrations of Zundel-like and intermediate geometries, broadened by the heterogeneity of aqueous configurations. There is a wide distribution of multidimensional potential shapes for the proton stretching vibration with varying degrees of potential asymmetry and confinement. Finally, we find specific cross peak patterns due to aqueous Zundel-like species. These studies provide clarity on highly debated spectral assignments and stringent spectroscopic benchmarks for future simulations.
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Affiliation(s)
- William B Carpenter
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - John H Hack
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Bogdan Dereka
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Andrei Tokmakoff
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
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19
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Franke PR, Duncan MA, Douberly GE. Infrared photodissociation spectroscopy and anharmonic vibrational study of the HO 4 + molecular ion. J Chem Phys 2020; 152:174309. [PMID: 32384862 DOI: 10.1063/5.0005975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular cations of HO4 + and DO4 + are produced in a supersonic expansion. They are mass-selected, and infrared photodissociation spectra of these species are measured with the aid of argon-tagging. Although previous theoretical studies have modeled these systems as proton-bound dimers of molecular oxygen, infrared spectra have free OH stretching bands, suggesting other isomeric structures. As a consequence, we undertook extensive computational studies. Our conformer search used a composite method based on an economical combination of single- and multi-reference theories. Several conformers were located on the quintet, triplet, and singlet surfaces, spanning in energy of only a few thousand wavenumbers. Most of the singlet and triplet conformers have pronounced multiconfigurational character. Previously unidentified covalent-like structures (H-O-O-O-O) on the singlet and triplet surfaces likely represent the global minima. In our experiments, HO4 + is formed in a relatively hot environment, and similar experiments have been shown capable of producing multiple conformers in low-lying electronic states. None of the predicted HO4 + isomers can be ruled out a priori based on energetic arguments. We interpret our argon-tagged spectra with Second-Order Vibrational Perturbation Theory with Resonances (VPT2+K). The presence of one or more covalent-like isomers is the only reasonable explanation for the spectral features observed.
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Affiliation(s)
- Peter R Franke
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Michael A Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Gary E Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
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20
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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] [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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21
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Yu Q, Bowman JM. Tracking Hydronium/Water Stretches in Magic H3O+(H2O)20 Clusters through High-level Quantum VSCF/VCI Calculations. J Phys Chem A 2020; 124:1167-1175. [DOI: 10.1021/acs.jpca.9b11983] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Qi Yu
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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22
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Capturing intrinsic site-dependent spectral signatures and lifetimes of isolated OH oscillators in extended water networks. Nat Chem 2019; 12:159-164. [PMID: 31767995 DOI: 10.1038/s41557-019-0376-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 10/11/2019] [Indexed: 02/01/2023]
Abstract
The extremely broad infrared spectrum of water in the OH stretching region is a manifestation of how profoundly a water molecule is distorted when embedded in its extended hydrogen-bonding network. Many effects contribute to this breadth in solution at room temperature, which raises the question as to what the spectrum of a single OH oscillator would be in the absence of thermal fluctuations and coupling to nearby OH groups. We report the intrinsic spectral responses of isolated OH oscillators embedded in two cold (~20 K), hydrogen-bonded water cages adopted by the Cs+·(HDO)(D2O)19 and D3O+·(HDO)(D2O)19 clusters. Most OH oscillators yield single, isolated features that occur with linewidths that increase approximately linearly with their redshifts. Oscillators near 3,400 cm-1, however, occur with a second feature, which indicates that OH stretch excitation of these molecules drives low-frequency, phonon-type motions of the cage. The excited state lifetimes inferred from the broadening are considered in the context of fluctuations in the local electric fields that are available even at low temperature.
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23
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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] [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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24
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Yu Q, Carpenter WB, Lewis NHC, Tokmakoff A, Bowman JM. High-Level VSCF/VCI Calculations Decode the Vibrational Spectrum of the Aqueous Proton. J Phys Chem B 2019; 123:7214-7224. [PMID: 31361141 DOI: 10.1021/acs.jpcb.9b05723] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The hydrated excess proton is a common species in aqueous chemistry, which complexes with water in a variety of structures. The infrared spectrum of the aqueous proton is particularly sensitive to this array of structures, which manifests as continuous IR absorption from 1000 to 3000 cm-1 known as the "proton continuum". Because of the extreme breadth of the continuum and strong anharmonicity of the involved vibrational modes, this spectrum has eluded straightforward interpretation and simulation. Using protonated water hexamer clusters from reactive molecular dynamics trajectories, and focusing on their central H+(H2O)2 structures' spectral contribution, we reproduce the linear IR spectrum of the aqueous proton with a high-level local monomer quantum method and highly accurate many-body potential energy surface. The accuracy of this approach is first verified in the vibrational spectra of the two isomers of the protonated water hexamer in the gas phase. We then apply this approach to 800 H+(H2O)6 clusters, also written as [H+(H2O)2](H2O)4, drawn from multistate empirical valence bond simulations of the bulk liquid to calculate the infrared spectrum of the aqueous proton complex. Incorporation of anharmonic effects to the vibrational potential and quantum mechanical treatment of the proton produces a better agreement to the infrared spectrum compared to that of the double-harmonic approximation. We assess the correlation of the proton stretching mode with different atomistic coordinates, finding the best correlation with ⟨ROH⟩, the expectation value of the proton-oxygen distance ROH. We also decompose the IR spectrum based on normal mode vibrations and ⟨ROH⟩ to provide insight on how different frequency regions in the continuum report on different configurations, vibrational modes, and mode couplings.
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Affiliation(s)
- Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation , Emory University , Atlanta , Georgia 30322 , United States
| | - William B Carpenter
- Department of Chemistry, James Frank Institute, and Institute for Biophysical Dynamics , The University of Chicago , Chicago , Illinois 60637 , United States
| | - Nicholas H C Lewis
- Department of Chemistry, James Frank Institute, and Institute for Biophysical Dynamics , The University of Chicago , Chicago , Illinois 60637 , United States
| | - Andrei Tokmakoff
- Department of Chemistry, James Frank Institute, and Institute for Biophysical Dynamics , The University of Chicago , Chicago , Illinois 60637 , United States
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation , Emory University , Atlanta , Georgia 30322 , United States
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25
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26
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Reese DL, Steele RP. Nuclear Motion in the Intramolecular Dihydrogen-Bound Regime of an Aminoborane Complex. J Phys Chem A 2019; 123:6547-6563. [DOI: 10.1021/acs.jpca.9b05219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Diana L. Reese
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Ryan P. Steele
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
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27
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Kundu A, Dahms F, Fingerhut BP, Nibbering ETJ, Pines E, Elsaesser T. Hydrated Excess Protons in Acetonitrile/Water Mixtures: Solvation Species and Ultrafast Proton Motions. J Phys Chem Lett 2019; 10:2287-2294. [PMID: 30999753 DOI: 10.1021/acs.jpclett.9b00756] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The solvation structure of protons in aqueous media is highly relevant to electric properties and to proton transport in liquids and membranes. At ambient temperature, polar liquids display structural fluctuations on femto- to picosecond time scales with a direct impact on proton solvation. We use two-dimensional infrared (2D-IR) spectroscopy to follow proton dynamics in acetonitrile/water mixtures with the Zundel cation H5O2+ prepared in neat acetonitrile as a benchmark. The 2D-IR spectra of the proton transfer mode of H5O2+ demonstrate stochastic large-amplitude motions in the double-minimum proton potential, driven by fluctuating electric fields. In all cases, the excess proton is embedded in a water dimer, forming an H5O2+ complex as the major solvation species. This observation is rationalized by quantum mechanics/molecular mechanics molecular dynamics simulations including up to four water molecules embedded in acetonitrile. The Zundel motif interacts with its closest water neighbor in an H7O3+ unit without persistent proton localization.
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Affiliation(s)
- Achintya Kundu
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , Berlin 12489 , Germany
| | - Fabian Dahms
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , Berlin 12489 , Germany
| | - Benjamin P Fingerhut
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , Berlin 12489 , Germany
| | - Erik T J Nibbering
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , Berlin 12489 , Germany
| | - Ehud Pines
- Department of Chemistry , Ben Gurion University of the Negev , Beer-Sheva 84105 , Israel
| | - Thomas Elsaesser
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , Berlin 12489 , Germany
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28
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Sibert EL. Modeling vibrational anharmonicity in infrared spectra of high frequency vibrations of polyatomic molecules. J Chem Phys 2019; 150:090901. [DOI: 10.1063/1.5079626] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Edwin L. Sibert
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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29
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Yu Q, Bowman JM. Classical, Thermostated Ring Polymer, and Quantum VSCF/VCI Calculations of IR Spectra of H7O3+ and H9O4+ (Eigen) and Comparison with Experiment. J Phys Chem A 2019; 123:1399-1409. [DOI: 10.1021/acs.jpca.8b11603] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Qi Yu
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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30
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Qu C, Bowman JM. Quantum approaches to vibrational dynamics and spectroscopy: is ease of interpretation sacrificed as rigor increases? Phys Chem Chem Phys 2019; 21:3397-3413. [DOI: 10.1039/c8cp04990d] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The subject of this Perspective is quantum approaches, beyond the harmonic approximation, to vibrational dynamics and IR spectroscopy.
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Affiliation(s)
- Chen Qu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University
- Atlanta
- USA
| | - Joel M. Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University
- Atlanta
- USA
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31
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Lewis NHC, Fournier JA, Carpenter WB, Tokmakoff A. Direct Observation of Ion Pairing in Aqueous Nitric Acid Using 2D Infrared Spectroscopy. J Phys Chem B 2018; 123:225-238. [DOI: 10.1021/acs.jpcb.8b10019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Nicholas H. C. Lewis
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| | - Joseph A. Fournier
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - William B. Carpenter
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| | - Andrei Tokmakoff
- Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
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32
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Dai Z, Shi L, Lu L, Sun Y, Lu X. Unique Structures and Vibrational Spectra of Protic Ionic Liquids Confined in TiO 2 Slits: The Role of Interfacial Hydrogen Bonds. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:13449-13458. [PMID: 30350690 DOI: 10.1021/acs.langmuir.8b02527] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The ionic liquid (IL)/titanium dioxide (TiO2) interface exists in many application systems, such as nanomaterial synthesis, catalysis, and electrochemistry systems. The nanoscale interfacial properties in the above systems are a common issue. However, directly detecting the interfacial properties of nanoconfined ILs by experimental methods is still challenging. To help better learn about the interfacial issue, molecular dynamics simulations have been performed to explore the structures, vibration spectra, and hydrogen bond (HB) properties at the IL/TiO2 interface. Ethylammonium nitrate (EAN) ILs confined in TiO2 slit pores with different pore widths were studied. A unique vibrational spectrum appeared for EAN ILs confined in a 0.7 nm TiO2 slit, and this phenomenon is related to interfacial hydrogen bonds (HBs). An analysis of the HB types indicated that the interfacial NH3+ group of the cations was in an asymmetric HB environment in the 0.7 nm TiO2 slit, which led to the disappearance of the symmetric N-H stretching mode. In addition, the significant increase in the HB strength between NH3+ groups and the TiO2 surface slowed down the stretching vibration of the N-H bond, resulting in one peak in the vibrational spectra at a lower frequency. For the first time, our simulation work establishes a molecular-level relationship between the vibrational spectrum and the local HB environment of nanoconfined ILs at the IL/TiO2 interface, and this relationship is helpful for interface design in related systems.
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Affiliation(s)
- Zhongyang Dai
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing Tech University , 5 Xinmofan Road , Nanjing 210009 , P. R. China
| | - Lili Shi
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing Tech University , 5 Xinmofan Road , Nanjing 210009 , P. R. China
| | - Linghong Lu
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing Tech University , 5 Xinmofan Road , Nanjing 210009 , P. R. China
| | - Yunhao Sun
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing Tech University , 5 Xinmofan Road , Nanjing 210009 , P. R. China
| | - Xiaohua Lu
- College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering , Nanjing Tech University , 5 Xinmofan Road , Nanjing 210009 , P. R. China
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33
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Roy TK, Kopysov V, Pereverzev A, Šebek J, Gerber RB, Boyarkin OV. Intrinsic structure of pentapeptide Leu-enkephalin: geometry optimization and validation by comparison of VSCF-PT2 calculations with cold ion spectroscopy. Phys Chem Chem Phys 2018; 20:24894-24901. [PMID: 30234204 DOI: 10.1039/c8cp03989e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The intrinsic structure of an opioid peptide [Ala2, Leu5]-leucine enkephalin (ALE) has been investigated using first-principles based vibrational self-consistent field (VSCF) theory and cold ion spectroscopy. IR-UV double resonance spectroscopy revealed the presence of only one highly abundant conformer of the singly protonated ALE, isolated and cryogenically cooled in the gas phase. High-level quantum mechanical calculations of electronic structures in conjunction with a systematic conformational search allowed for finding a few low-energy candidate structures. In order to identify the observed structure, we computed vibrational spectra of the candidate structures and employed the theory at the semi-empirically scaled harmonic level and at the first-principles based anharmonic VSCF levels. The best match between the calculated "anharmonic" and the measured spectra appeared, indeed, for the most stable candidate. An average of two spectra calculated with different quantum mechanical potentials is proposed for the best match with experiment. The match thus validates the calculated intrinsic structure of ALE and demonstrates the predictive power of first-principles theory for solving structures of such large molecules.
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Affiliation(s)
- Tapta Kanchan Roy
- Department of Chemistry and Chemical Sciences, Central University of Jammu, Rahya-Suchani (Bagla), Jammu 181143, India
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34
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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] [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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35
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McDonald DC, Wagner JP, McCoy AB, Duncan MA. Near-Infrared Spectroscopy and Anharmonic Theory of Protonated Water Clusters: Higher Elevations in the Hydrogen Bonding Landscape. J Phys Chem Lett 2018; 9:5664-5671. [PMID: 30205006 DOI: 10.1021/acs.jpclett.8b02499] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Near-infrared spectroscopy measurements are presented for protonated water clusters, H+(H2O) n, in the size range of n = 1-8. Clusters are produced in a pulsed-discharge supersonic expansion, mass selected, and studied with infrared laser photodissociation spectroscopy in the regions of 3600-4550 and 4850-7350 cm-1. Although there is some variation with cluster size, the main features of these spectra are a broad absorption near 5300 cm-1, a sharp doublet near 7200 cm-1, as well as a structured absorption near 4100 cm-1 for n ≥ 2. The vibrational patterns measured for the hydronium, Zundel, and Eigen ions are compared to those predicted by different forms of anharmonic theory. Second-order vibrational perturbation theory (VPT2) and a local mode treatment of the OH stretches both capture key aspects of the spectra but suffer understandable deficiencies in the quantitative description of band positions and intensities.
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Affiliation(s)
- D C McDonald
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | - J P Wagner
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | - A B McCoy
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | - M A Duncan
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
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Heindel JP, Yu Q, Bowman JM, Xantheas SS. Benchmark Electronic Structure Calculations for H3O+(H2O)n, n = 0–5, Clusters and Tests of an Existing 1,2,3-Body Potential Energy Surface with a New 4-Body Correction. J Chem Theory Comput 2018; 14:4553-4566. [DOI: 10.1021/acs.jctc.8b00598] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Joseph P. Heindel
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, 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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Affiliation(s)
- Chen Qu
- Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Qi Yu
- Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Joel M. Bowman
- Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
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Esser TK, Knorke H, Asmis KR, Schöllkopf W, Yu Q, Qu C, Bowman JM, Kaledin M. Deconstructing Prominent Bands in the Terahertz Spectra of H 7O 3+ and H 9O 4+: Intermolecular Modes in Eigen Clusters. J Phys Chem Lett 2018; 9:798-803. [PMID: 29360366 DOI: 10.1021/acs.jpclett.7b03395] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report experimental vibrational action spectra (210-2200 cm-1) and calculated IR spectra, using recent ab initio potential energy and dipole moment surfaces, of H7O3+ and H9O4+. We focus on prominent far-IR bands, which postharmonic analyses show, arise from two types of intermolecular motions, i.e., hydrogen bond stretching and terminal water wagging modes, that are similar in both clusters. The good agreement between experiment and theory further validates the accuracy of the potential and dipole moment surfaces, which was used in a recent theoretical study that concluded that infrared photodissociation spectra of the cold clusters correspond to the Eigen isomer. The comparison between theory and experiment adds further confirmation of the need of postharmonic analysis for these clusters.
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Affiliation(s)
- Tim K Esser
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, 04103 Leipzig, Germany
| | - Harald Knorke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, 04103 Leipzig, Germany
| | - Knut R Asmis
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, 04103 Leipzig, Germany
| | - Wieland Schöllkopf
- Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany
| | - Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States
| | - Chen Qu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States
| | - Martina Kaledin
- Department of Chemistry and Biochemistry, Kennesaw State University , Kennesaw, Georgia 30144, United States
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Dzugan LC, DiRisio RJ, Madison LR, McCoy AB. Spectral signatures of proton delocalization in H+(H2O)n=1−4 ions. Faraday Discuss 2018; 212:443-466. [DOI: 10.1039/c8fd00120k] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Vibrational couplings in protonated water clusters are described by harmonic analysis, vibrational perturbation theory (VPT2) and diffusion Monte Carlo (DMC) approaches.
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Affiliation(s)
- Laura C. Dzugan
- Department of Chemistry and Biochemistry
- The Ohio State University
- Columbus
- USA
| | | | | | - Anne B. McCoy
- Department of Chemistry
- University of Washington
- Seattle
- USA
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Yu Q, Bowman JM. High-Level Quantum Calculations of the IR Spectra of the Eigen, Zundel, and Ring Isomers of H +(H 2O) 4 Find a Single Match to Experiment. J Am Chem Soc 2017; 139:10984-10987. [PMID: 28756669 DOI: 10.1021/jacs.7b05459] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The protonated water tetramer H+(H2O)4, often written as the Eigen cluster, H3O+(H2O)3, plays a central role in studies of the hydrated proton. The cluster has been investigated spectroscopically both experimentally and theoretically with some differences and controversies. The major issue stems from the existence of higher-energy Zundel isomers of this cluster and the role these isomers might play in the IR spectra. Settling this fundamental issue is one goal of this Communication, where high-level quantum calculations of the IR spectra of the Eigen and three isomeric forms of this cluster are presented. These calculations make use of a many-body representation of the potential and dipole moment surfaces and VSCF/VCI calculations of vibrational eigenstates and the IR spectrum. The calculated spectra for the Eigen H3O+(H2O)3 and D3O+(D2O)3 isomers compare very well with experiment. The calculated spectra for the cis and trans-Zundel and ring isomers show prominent features that do not match with experiment but which can guide future experiments to search for these interesting and important isomers.
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Affiliation(s)
- Qi Yu
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States
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