51
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Braams BJ, Bowman JM. Permutationally invariant potential energy surfaces in high dimensionality. INT REV PHYS CHEM 2009. [DOI: 10.1080/01442350903234923] [Citation(s) in RCA: 535] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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52
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Vendrell O, Gatti F, Meyer HD. Full dimensional (15 dimensional) quantum-dynamical simulation of the protonated water-dimer IV: Isotope effects in the infrared spectra of D(D2O)2+, H(D2O)2+, and D(H2O)2+ isotopologues. J Chem Phys 2009; 131:034308. [DOI: 10.1063/1.3183166] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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53
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Fridgen TD. Infrared consequence spectroscopy of gaseous protonated and metal ion cationized complexes. MASS SPECTROMETRY REVIEWS 2009; 28:586-607. [PMID: 19343731 DOI: 10.1002/mas.20224] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In this article, the new and exciting techniques of infrared consequence spectroscopy (sometimes called action spectroscopy) of gaseous ions are reviewed. These techniques include vibrational predissociation spectroscopy and infrared multiple photon dissociation spectroscopy and they typically complement one another in the systems studied and the information gained. In recent years infrared consequence spectroscopy has provided long-awaited direct evidence into the structures of gaseous ions from organometallic species to strong ionic hydrogen bonded structures to large biomolecules. Much is being learned with respect to the structures of ions without their stabilizing solvent which can be used to better understand the effect of solvent on their structures. This review mainly covers the topics with which the author has been directly involved in research: structures of proton-bound dimers, protonated amino acids and DNA bases, amino acid and DNA bases bound to metal ions and, more recently, solvated ionic complexes. It is hoped that this review reveals the impact that infrared consequence spectroscopy has had on the field of gaseous ion chemistry.
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Affiliation(s)
- Travis D Fridgen
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada A1B 3X7.
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54
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Vendrell O, Brill M, Gatti F, Lauvergnat D, Meyer HD. Full dimensional (15-dimensional) quantum-dynamical simulation of the protonated water-dimer III: Mixed Jacobi-valence parametrization and benchmark results for the zero point energy, vibrationally excited states, and infrared spectrum. J Chem Phys 2009; 130:234305. [DOI: 10.1063/1.3152488] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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55
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Kaledin M, Kaledin AL, Bowman JM, Ding J, Jordan KD. Calculation of the Vibrational Spectra of H5O2+ and Its Deuterium-Substituted Isotopologues by Molecular Dynamics Simulations. J Phys Chem A 2009; 113:7671-7. [DOI: 10.1021/jp900737r] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Martina Kaledin
- Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, Georgia 30144
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56
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Kaledin M, Moffitt JM, Clark CR, Rizvi F. Ab Initio Molecular Dynamics Simulations of the Infrared Spectra of H3O2− and D3O2−. J Chem Theory Comput 2009; 5:1328-36. [DOI: 10.1021/ct8004485] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Martina Kaledin
- Chemistry and Biochemistry, Kennesaw State University, 1000 Chastain Rd., Box 1203, Kennesaw, Georgia 30144
| | - John M. Moffitt
- Chemistry and Biochemistry, Kennesaw State University, 1000 Chastain Rd., Box 1203, Kennesaw, Georgia 30144
| | - Craig R. Clark
- Chemistry and Biochemistry, Kennesaw State University, 1000 Chastain Rd., Box 1203, Kennesaw, Georgia 30144
| | - Fareeha Rizvi
- Chemistry and Biochemistry, Kennesaw State University, 1000 Chastain Rd., Box 1203, Kennesaw, Georgia 30144
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57
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Vendrell O, Gatti F, Meyer HD. Strong Isotope Effects in the Infrared Spectrum of the Zundel Cation. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200804646] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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58
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Vendrell O, Gatti F, Meyer HD. Strong Isotope Effects in the Infrared Spectrum of the Zundel Cation. Angew Chem Int Ed Engl 2009; 48:352-5. [DOI: 10.1002/anie.200804646] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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59
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Ricks AM, Douberly GE, Duncan MA. Infrared spectroscopy of the protonated nitrogen dimer: The complexity of shared proton vibrations. J Chem Phys 2009. [DOI: 10.1063/1.3224155] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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60
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Gardenier GH, Roscioli JR, Johnson MA. Intermolecular Proton Binding in the Presence of a Large Electric Dipole: Ar-Tagged Vibrational Predissociation Spectroscopy of the CH3CN·H+·OH2 and CH3CN·D+·OD2 Complexes. J Phys Chem A 2008; 112:12022-6. [DOI: 10.1021/jp800948s] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- George H. Gardenier
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520
| | - Joseph R. Roscioli
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520
| | - Mark A. Johnson
- Sterling Chemistry Laboratory, Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520
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61
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Bowman JM, Carrington T, Meyer HD. Variational quantum approaches for computing vibrational energies of polyatomic molecules. Mol Phys 2008. [DOI: 10.1080/00268970802258609] [Citation(s) in RCA: 303] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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62
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Sumner I, Iyengar SS. Combining quantum wavepacketab initiomolecular dynamics with QM/MM and QM/QM techniques: Implementation blendingONIOMand empirical valence bond theory. J Chem Phys 2008; 129:054109. [DOI: 10.1063/1.2956496] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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63
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Mitchell-Koch KR, Thompson WH. Infrared spectra of a model phenol-amine proton transfer complex in nanoconfined CH3Cl. J Phys Chem B 2008; 112:7448-59. [PMID: 18517239 DOI: 10.1021/jp076714e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The vibrational spectra of a model phenol-amine proton transfer complex dissolved in CH3Cl solvent confined in a 12 A radius spherical hydrophobic cavity were calculated using mixed quantum-classical molecular dynamics simulations. The reaction free energy of the proton transfer complex was varied in order to explore the contributions to the vibrational absorption band from product and reactant species. The vibrational spectra of the model proton transfer complex resulted in motionally narrowed spectral linewidths with two distinct peaks for products and reactants in cases where the system undergoes chemical exchange. It was found that the n=1 and n=2 vibrational excited states combine to form diabatic states such that the spectra have contributions from both n=0 --> n=1 and n=0 --> n=2 transitions. A strong relationship between the instantaneous vibrational frequency and a collective solvent coordinate was found that assists in understanding the origin of the spectral features.
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64
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Lammers S, Lutz S, Meuwly M. Reactive force fields for proton transfer dynamics. J Comput Chem 2008; 29:1048-63. [PMID: 18072179 DOI: 10.1002/jcc.20864] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A force field-inspired method based on fitted, high-quality multidimensional potential energy surfaces to follow proton transfer (PT) reactions in molecular dynamics simulations is presented. In molecular mechanics with proton transfer (MMPT) a system is partitioned into a region where proton transfer takes place and the remaining degrees of freedom which are treated with a conventional force field. The implementation of the method and applications to specific chemically and biologically relevant scenarios are presented. MMPT is developed in view of two primary areas in mind: to follow the molecular dynamics of proton transfer in the condensed phase on realistic time scales and to adapt the shape (morphing) of the potential energy surface for specific applications. MMPT is applied to PT in protonated ammonia dimer, double proton transfer in 2-pyridone-2-hydroxypyridine, and the first step of PT from a protein side-chain towards a buried [3Fe4S] cluster in ferredoxin I. Specific findings of the work include the fundamental role of the N-N vibration as the gating mode for PT in NH4+...NH3 and the qualitative understanding of PT from the protein to a metastable active-site water molecule in Ferredoxin I.
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Affiliation(s)
- Sven Lammers
- Chemistry Department, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
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65
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Li X, Moore DT, Iyengar SS. Insights from first principles molecular dynamics studies toward infrared multiple-photon and single-photon action spectroscopy: Case study of the proton-bound dimethyl ether dimer. J Chem Phys 2008; 128:184308. [DOI: 10.1063/1.2903446] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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66
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Douberly GE, Ricks AM, Ticknor BW, McKee WC, Schleyer PVR, Duncan MA. Infrared Photodissociation Spectroscopy of Protonated Acetylene and Its Clusters. J Phys Chem A 2008; 112:1897-906. [DOI: 10.1021/jp710808e] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- G. E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - A. M. Ricks
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - B. W. Ticknor
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - W. C. McKee
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - P. v. R. Schleyer
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
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67
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Douberly GE, Ricks AM, Ticknor BW, Duncan MA. Structure of Protonated Carbon Dioxide Clusters: Infrared Photodissociation Spectroscopy and ab Initio Calculations. J Phys Chem A 2008; 112:950-9. [DOI: 10.1021/jp7098587] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- G. E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - A. M. Ricks
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - B. W. Ticknor
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
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68
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The Study of Dynamically Averaged Vibrational Spectroscopy of Atmospherically Relevant Clusters Using Ab Initio Molecular Dynamics in Conjunction with Quantum Wavepackets. ADVANCES IN QUANTUM CHEMISTRY 2008. [DOI: 10.1016/s0065-3276(07)00216-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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69
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Huang X, Habershon S, Bowman JM. Comparison of quantum, classical, and ring-polymer molecular dynamics infra-red spectra of Cl−(H2O) and H+(H2O)2. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2007.11.048] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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70
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Vendrell O, Gatti F, Meyer HD. Full dimensional (15-dimensional) quantum-dynamical simulation of the protonated water dimer. II. Infrared spectrum and vibrational dynamics. J Chem Phys 2007; 127:184303. [DOI: 10.1063/1.2787596] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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71
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Vendrell O, Gatti F, Lauvergnat D, Meyer HD. Full-dimensional (15-dimensional) quantum-dynamical simulation of the protonated water dimer. I. Hamiltonian setup and analysis of the ground vibrational state. J Chem Phys 2007; 127:184302. [DOI: 10.1063/1.2787588] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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72
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Park M, Shin I, Singh NJ, Kim KS. Eigen and Zundel Forms of Small Protonated Water Clusters: Structures and Infrared Spectra. J Phys Chem A 2007; 111:10692-702. [PMID: 17910422 DOI: 10.1021/jp073912x] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The spectral properties of protonated water clusters, especially the difference between Eigen (H3O+) and Zundel (H5O2+) conformers and the difference between their unhydrated and dominant hydrated forms are investigated with the first principles molecular dynamics simulations as well as with the high level ab initio calculations. The vibrational modes of the excess proton in H3O+ are sensitive to the hydration, while those in H5O2+ are sensitive to the messenger atom such as Ar (which was assumed to be weakly bound to the water cluster during acquisitions of experimental spectra). The spectral feature around approximately 2700 cm-1 (experimental value: 2665 cm-1) for the Eigen moiety appears when H3O+ is hydrated. This feature corresponds to the hydrating water interacting with H3O+, so it cannot appear in the Eigen core. Thus, H3O+ alone would be somewhat different from the Eigen forms in water. For the Zundel form (in particular, H5O2+), there have been some differences in spectral features among different experiments as well as between experiments and theory. When an Ar messenger atom is introduced at a specific temperature corresponding to the experimental condition, the calculated vibrational spectra for H5O2+.Ar are in good agreement with the experimental infrared spectra showing the characteristic Zundel frequency at approximately 1770 cm-1. Thus, the effect of hydration, messenger atom Ar, and temperature are crucial to elucidating the nature of vibrational spectra of Eigen and Zundel forms and to assigning the vibrational modes of small protonated water clusters.
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Affiliation(s)
- Mina Park
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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73
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Vendrell O, Gatti F, Meyer HD. Dynamics and Infrared Spectroscopy of the Protonated Water Dimer. Angew Chem Int Ed Engl 2007; 46:6918-21. [PMID: 17676569 DOI: 10.1002/anie.200702201] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Oriol Vendrell
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
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74
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Vendrell O, Gatti F, Meyer HD. Dynamik und Infrarotspektroskopie des protonierten Wasser-Dimers. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200702201] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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75
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MacAleese L, Maître P. Infrared spectroscopy of organometallic ions in the gas phase: from model to real world complexes. MASS SPECTROMETRY REVIEWS 2007; 26:583-605. [PMID: 17471578 DOI: 10.1002/mas.20138] [Citation(s) in RCA: 219] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Gas phase mid-infrared spectroscopy of molecular ions can nowadays be performed with high performance mass spectrometers coupled to free electron lasers (FEL). The wide and continuous tunability of highly intense FELs in the mid-infrared region can be exploited for performing infrared multiple photon dissociation (IRMPD) spectroscopy of molecular ions. This review will focus on gas phase IRMPD spectroscopic investigations aiming at probing the structure and the reactivity of transition metal complexes. The performance of infrared spectroscopy for characterizing the coordination mode of polydentate ligands and the spin state of the metal will be illustrated. Infrared spectroscopy has also been exploited to probe the reactivity of metal complexes, and a special attention will be given to the infrared spectroscopy of reactive intermediates.
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Affiliation(s)
- Luke MacAleese
- Laboratoire de Chimie Physique, UMR8000 CNRS and Université Paris-Sud 11, Faculté des Sciences, Bâtiment 350, 91405 Orsay Cedex, France
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76
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Abstract
A proton shared between two closed-shell molecules, [A.H+.B], constitutes a ubiquitous soft binding motif in biological processes. The vibrational transitions associated with the shared proton, which provide a direct probe of this interaction, have been extensively studied in the condensed phase but have yielded only limited detailed information because of their diffuse character. We exploited recent advances in gas-phase ion spectroscopy to identify sharp spectral features that can be assigned to both the shared proton and the two tethered molecules in a survey of 18 cold, isolated [A.H+.B] ions. These data yield a picture of the intermolecular proton bond at a microscopic scale, facilitating analysis of its properties within the context of a floppy polyatomic molecule.
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Affiliation(s)
- J R Roscioli
- Sterling Chemistry Laboratory, Yale University, Post Office Box 208107, New Haven, CT 06520, USA
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77
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Lammers S, Meuwly M. Investigating the relationship between infrared spectra of shared protons in different chemical environments: a comparison of protonated diglyme and protonated water dimer. J Phys Chem A 2007; 111:1638-47. [PMID: 17295453 DOI: 10.1021/jp065323h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The energetics, dynamics, and infrared spectroscopy of the shared proton in different chemical environments is investigated using molecular dynamics simulations. A three-dimensional potential energy surface (PES) suitable for describing proton transfer between an acceptor and a donor oxygen atom is combined with an all-atom force field to carry out reactive molecular dynamics simulations. The construction of the fully dimensional PES is inspired from the established mixed quantum mechanics/molecular mechanics treatment of larger systems. The "morphing potential" method is used to transform the generic PES for proton transfer along an O...H+...O motif into a three-dimensional PES for proton transfer in protonated diglyme. Using molecular dynamics simulations at finite temperature, the gas phase infrared spectra are calculated for both species from the Fourier transform of the dipole moment autocorrelation function. For protonated diglyme the modes involving the H+ motion are strongly mixed with other degrees of freedom. At low temperature, the O...H+...O asymmetric stretching vibration is found at 870 cm-1, whereas for H5O2+ this band is at 724 cm-1. As expected, the vibrational bands of protonated diglyme show no temperature dependence whereas for H5O2+ at T = 100 K the proton transfer mode is found at 830 cm-1, in good agreement with 861 cm-1 from very recent molecular dynamics simulations.
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Affiliation(s)
- Sven Lammers
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
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78
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Stoyanov ES, Reed CA. IR Spectrum of the H5O2+ Cation in the Context of Proton Disolvates L−H+−L. J Phys Chem A 2006; 110:12992-3002. [PMID: 17134158 DOI: 10.1021/jp062879w] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The H(5)O(2)(+) ion has been studied in chlorocarbon, benzene, and weakly coordinating anion environments to bridge the gap between the gas-phase and traditional condensed-phase investigations. Symmetrical cations of the type [H(5)O(2)(+) x 4Solv] are formed via H-bonding with the terminal O-H groups. In the infrared spectrum, the nu(s)OH and nu(as)OH vibrations behave in a manner similar to those of common water molecules: the stronger is the H-bonding interaction with the surroundings, the lower is the frequency shift. A consistent pattern of IR bands from the central O-H(+)-O group is identified, regardless of the strength of the interaction of H(5)O(2)(+) with its environment. Three intense bands develop: a (860-995 cm-1), b (1045-1101 cm(-1)), and c (1672-1700 cm(-1)), as well as two weak bands, d ( approximately 1300 cm(-1)) and e ( approximately 1400-1500 cm(-1)). These fingerprint bands are highly characteristic for vibrations of O-H-O group irrespective of formal charge. They are seen in symmetrical proton disolvates of the type L-H(+)-L, where L is an O-atom donor (alcohol, ether, ketone, phosphate, etc.), and in [A-H-A](-) acid salts (A(-) = oxyanion). The commonality is equivalency of the two O-atoms, a short O...O distance (ca. 2.40 Angstrom), and a flat-bottomed potential well for the bridging proton, that is, a short, strong, low-barrier H-bond. Assignments for bands a-e are suggested in an attempt to resolve inconsistencies between experimental and calculated data.
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Affiliation(s)
- Evgenii S Stoyanov
- Department of Chemistry, University of California, Riverside, Riverside, California 92521, USA
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79
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Fridgen TD, McMahon TB, Maître P, Lemaire J. Experimental infrared spectra of Cl−(ROH) (R = H, CH3, CH3CH2) complexes in the gas-phase. Phys Chem Chem Phys 2006; 8:2483-90. [PMID: 16721432 DOI: 10.1039/b603102a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Infrared multiple photon dissociation spectra for the chloride ion solvated by either water, methanol or ethanol have been recorded using an FTICR spectrometer coupled to a free-electron laser, and are presented here along with assignments to the observed bands. The assignments made to the Cl(-)/H(2)O, Cl(-)(CH(3)OH), and Cl(-)(CH(3)CH(2)OH) spectra are based on comparison with the neutral H(2)O, CH(3)OH, and CH(3)CH(2)OH spectra, respectively. This work confirms that a band observed around 1400 cm(-1) in the Cl(-)(H(2)O) spectrum is not due to the Ar tag in Ar predissociation spectra. The carrier of this band is, most likely, the first overtone of the OHCl bend. Based on the position of the overtone in the IRMPD spectrum, 1375 cm(-1), the fundamental must occur very close to 700 cm(-1) and observation of this band should aid theoretical treatments of the spectrum of this complex. B3LYP/6-311++G(2df,2pd) calculations are shown to reproduce the IRMPD spectra of all three solvated chloride species. They also predict that attaching one or two Ar atoms to the Cl(-)(H(2)O) complex results in a shift of no more than a few wavenumbers in the fundamental bands for the bare complex, in agreement with previous experiment. For both alcohol-Cl(-) complexes, the S(N)2 "backside attack" isomers are not observed and Cl(-) is predicted theoretically, and confirmed experimentally, to be bound to the hydroxyl hydrogen. For Cl(-)(CH(3)CH(2)OH), the trans and gauche conformers are similar in energy, with the gauche conformer predicted to be thermodynamically favoured. The experimental infrared spectrum agrees well with that predicted for the gauche conformer but a mixture of gauche and anti conformers cannot be ruled out based on the experimental spectra nor on the computed thermochemistry.
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Affiliation(s)
- Travis D Fridgen
- Department of Chemistry, Memorial University of Newfoundland, St. John's, NL, Canada.
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