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Salbaing T, Comte D, Lavy L, Lissillour H, Ospina LP, Bertier P, Feketeová L, Calvo F, Farizon B, Farizon M, Märk T. Water molecule elimination from the protonated methanol dimer ion-An example of a size-selective intracluster reaction. J Chem Phys 2024; 160:094301. [PMID: 38436443 DOI: 10.1063/5.0190182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/12/2024] [Indexed: 03/05/2024] Open
Abstract
The abundance of extraterrestrial methanol makes the reaction between methanol molecules in a molecular cluster a possible key step in the search for mechanisms for the formation of more complex molecules under the conditions of the interstellar medium as well as circumstellar and planetary atmospheres. The reaction leading to the formation of the dimethyl ether ion from a methanol molecule interacting with a protonated methanol ion via the elimination of a water molecule is a basic mechanism for the formation of complex organic molecules. Here, we experimentally examine such reactions in the gas phase, analyzing the production and reactivity of protonated cluster ions formed by the ionization of a supersonic jet of methanol. Focusing especially on the post-collisional relaxation of the protonated methanol dimer and trimer ions after high-energy single collisions, the results indicate a strong size selectivity favoring the occurrence of this reaction only in the dimer ion. To elucidate this behavior, the velocity distribution of the eliminated water molecule was measured using an event-by-event coincidence analysis. These results are interpreted using quantum chemical calculations of the dissociation pathways. It turns out that in the dimer case, two transition states are able to contribute to this intracluster reaction. In the trimer case, methanol evaporation appears as the most energetically favorable relaxation pathway.
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Affiliation(s)
- Thibaud Salbaing
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
| | - Denis Comte
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
- Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität, 6020 Innsbruck, Austria
| | - Léo Lavy
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
| | - Hector Lissillour
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
| | - Laura Parrado Ospina
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
| | - Paul Bertier
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
| | - Linda Feketeová
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
| | - Florent Calvo
- Université Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
| | - Bernadette Farizon
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
| | - Michel Farizon
- Université Claude Bernard Lyon 1, IP2I Lyon, UMR 5822, CNRS/IN2P3, F-69622 Villeurbanne, France
| | - Tilmann Märk
- Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität, 6020 Innsbruck, Austria
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2
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Shinkai T, Hsu PJ, Fujii A, Kuo JL. Infrared spectroscopy and theoretical structure analyses of protonated fluoroalcohol clusters: the impact of fluorination on the hydrogen bond networks. Phys Chem Chem Phys 2022; 24:12631-12644. [PMID: 35579401 DOI: 10.1039/d2cp01300b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To explore the impact of fluorination on the hydrogen bond networks of protonated alkylalcohols, infrared spectroscopy and theoretical computations of protonated 2,2,2-trifluoroethanol clusters, H+(TFE)n, (n = 4-7), were performed. It has been demonstrated that the development of the hydrogen bond networks from a linear type to cyclic types occurs in this size region for the protonated alkylalcohol clusters. In contrast, infrared spectroscopy of H+(TFE)n in the OH/CH stretch region clearly indicated that the linear type structures are held in the whole size range, irrespective of temperature of the clusters. The extensive stable isomer structure search of H+(TFE)n based on our latest sampling approach supported the strong preference of the linear type hydrogen bond networks. Detailed analyses of the free OH stretching vibrational bands evidenced the intra- and intermolecular OH⋯FC interactions in the clusters. In addition, infrared spectra of protonated clusters of 2,2-difluoroethanol, 2,2-difluoropropanol, and 3,3,3-trifluoropropanol were measured for n = 4 and 5, and their spectra also indicated the effective inhibition of the cyclic hydrogen bond network formation by the fluorination.
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Affiliation(s)
- Takahiro Shinkai
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
| | - Po-Jen Hsu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
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3
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Kato T, Fujii A. How many methanol molecules effectively solvate an excess proton in the gas phase? Infrared spectroscopy of H +(methanol) n-benzene clusters. Phys Chem Chem Phys 2021; 24:163-171. [PMID: 34878469 DOI: 10.1039/d1cp04689f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
An excess proton in a hydrogen-bonded system enhances the strength of hydrogen bonds of the surrounding molecules. The extent of this influence can be a measure of the number of molecules effectively solvating the excess proton. Such extent in methanol has been discussed by the observation of the π-hydrogen-bonded OH stretch bands of the terminal sites of protonated methanol clusters, H+(methanol)n, in benzene solutions, and it has been concluded that ∼8 molecules effectively solvate the excess proton (Stoyanov et al., Chem. Eur. J. 2008, 14, 3596-3604). In the present study, we performed infrared spectroscopy of H+(methanol)n-benzene clusters in the gas phase. The cluster size and hydrogen-bonded network structure are identified by the tandem mass spectrometric technique and the comparison of the observed infrared spectra with density functional theory calculations. Though changes of the preferred hydrogen bond network type occur with the increase of cluster size in the gas phase clusters, the observed size dependence of the π-hydrogen bonded OH frequency agrees well with that in the benzene solutions. This means that the observations in both the gas and condensed phases catch the same physical essence of the excess proton solvation by methanol.
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Affiliation(s)
- Takeru Kato
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
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4
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Mechanisms of sequential ion-molecule reactions in protonated methanol using mass spectrometry, ab initio methods, and statistical modeling. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.110420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Sugawara N, Hsu PJ, Fujii A, Kuo JL. Competition between hydrogen bonds and van der Waals forces in intermolecular structure formation of protonated branched-chain alcohol clusters. Phys Chem Chem Phys 2018; 20:25482-25494. [PMID: 30276413 DOI: 10.1039/c8cp05222k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To investigate the influence of bulky alkyl groups on hydrogen-bonded (H-bonded) network structures of alcohols, infrared (IR) spectra of protonated clusters of 2-propanol (2-PrOH) and tert-butyl alcohol (t-BuOH) were observed in the OH and CH stretch regions. In addition, by varying the tag species, the temperature dependence profile of the isomer population of H+(t-BuOH)n was revealed. An extensive search for stable isomers was performed using dispersion-corrected density functional theory methods, and temperature-dependent IR spectral simulations were done on the basis of the harmonic superposition approximation. The computational results qualitatively agreed with the observed size and temperature dependence of the H-bonded network structures of these protonated bulky alcohol clusters. However, the difficulty in the quantitative evaluation of dispersion was also demonstrated. It was shown that H+(2-PrOH)n (n = 4-7) have essentially the same network structures as the protonated normal alcohol clusters studied so far. On the other hand, H+(t-BuOH)n (n = 4-8) showed a clear preference for the smaller-membered ring structures, that is very different from the preference of the protonated normal alcohol clusters. The origin of the different structure preferences was discussed in terms of the steric effect and dispersion.
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Affiliation(s)
- Natsuko Sugawara
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
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6
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Fujii A, Sugawara N, Hsu PJ, Shimamori T, Li YC, Hamashima T, Kuo JL. Hydrogen bond network structures of protonated short-chain alcohol clusters. Phys Chem Chem Phys 2018; 20:14971-14991. [DOI: 10.1039/c7cp08072g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Protonated alcohol clusters enable extraction of the physical essence of the nature of hydrogen bond networks.
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Affiliation(s)
- Asuka Fujii
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Natsuko Sugawara
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Po-Jen Hsu
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Takuto Shimamori
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Ying-Cheng Li
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Toru Hamashima
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
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7
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Li YC, Hamashima T, Yamazaki R, Kobayashi T, Suzuki Y, Mizuse K, Fujii A, Kuo JL. Hydrogen-bonded ring closing and opening of protonated methanol clusters H+(CH3OH)n (n = 4–8) with the inert gas tagging. Phys Chem Chem Phys 2015; 17:22042-53. [DOI: 10.1039/c5cp03379a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Temperature dependence of hydrogen bond network structures of protonated methanol clusters is explored by IR spectroscopy and DFT simulations.
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Affiliation(s)
- Ying-Cheng Li
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taiwan
| | - Toru Hamashima
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Ryoko Yamazaki
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Tomohiro Kobayashi
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Yuta Suzuki
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Kenta Mizuse
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Asuka Fujii
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taiwan
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8
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Fifen JJ, Nsangou M, Dhaouadi Z, Motapon O, Jaidane NE. Structures of protonated methanol clusters and temperature effects. J Chem Phys 2013; 138:184301. [DOI: 10.1063/1.4802480] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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9
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Fifen JJ, Nsangou M, Dhaouadi Z, Motapon O, Jaidane NE. Solvation Energies of the Proton in Methanol. J Chem Theory Comput 2013; 9:1173-81. [PMID: 26588760 DOI: 10.1021/ct300669v] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
pKa's, proton affinities, and proton dissociation free energies characterize numerous properties of drugs and the antioxidant activity of some chemical compounds. Even with a higher computational level of theory, the uncertainty in the proton solvation free energy limits the accuracy of these parameters. We investigated the thermochemistry of the solvation of the proton in methanol within the cluster-continuum model. The scheme used involves up to nine explicit methanol molecules, using the IEF-PCM and the strategy based on thermodynamic cycles. All computations were performed at B3LYP/6-31++G(dp) and M062X/6-31++G(dp) levels of theory. It comes out from our calculations that the functional M062X is better than B3LYP, on the evaluation of gas phase clustering energies of protonated methanol clusters, per methanol stabilization of neutral methanol clusters and solvation energies of the proton in methanol. The solvation free energy and enthalpy of the proton in methanol were obtained after converging the partial solvation free energy of the proton in methanol and the clustering free energy of protonated methanol clusters, as the cluster size increases. Finally, the recommended values for the solvation free energy and enthalpy of the proton in methanol are -257 and -252 kcal/mol, respectively.
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Affiliation(s)
- Jean Jules Fifen
- University of Ngaoundere, Faculty of Science, P.O. Box 454, Ngaoundere, Cameroon.,Fundamental Physics Lab, Graduate Training Unit in Physics and Engineering Sciences, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Mama Nsangou
- University of Ngaoundere, Faculty of Science, P.O. Box 454, Ngaoundere, Cameroon.,University of Maroua, P.O. Box 46, Maroua, Cameroon
| | - Zoubeida Dhaouadi
- Laboratoire de Spectroscopie Atomique et Moléculaire, Faculté des Sciences de Tunis, Université de Tunis El Manar, Campus Universitaire 1060, Tunis, Tunisia
| | - Ousmanou Motapon
- Fundamental Physics Lab, Graduate Training Unit in Physics and Engineering Sciences, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Nejm-Eddine Jaidane
- Laboratoire de Spectroscopie Atomique et Moléculaire, Faculté des Sciences de Tunis, Université de Tunis El Manar, Campus Universitaire 1060, Tunis, Tunisia
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10
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Kobayashi T, Shishido R, Mizuse K, Fujii A, Kuo JL. Structures of hydrogen bond networks formed by a few tens of methanol molecules in the gas phase: size-selective infrared spectroscopy of neutral and protonated methanol clusters. Phys Chem Chem Phys 2013; 15:9523-30. [DOI: 10.1039/c3cp50985k] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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12
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Kuo JL, Xie ZZ, Bing D, Fujii A, Hamashima T, Suhara KI, Mikami N. Comprehensive Analysis of the Hydrogen Bond Network Morphology and OH Stretching Vibrations in Protonated Methanol−Water Mixed Clusters, H+(MeOH)1(H2O)n (n = 1−8). J Phys Chem A 2008; 112:10125-33. [DOI: 10.1021/jp8057299] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jer-Lai Kuo
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, and Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Zhi-zhong Xie
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, and Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Dan Bing
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, and Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Asuka Fujii
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, and Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Toru Hamashima
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, and Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Ken-ichiro Suhara
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, and Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Naohiko Mikami
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, and Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
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13
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Tono K, Kuo JL, Tada M, Fukazawa K, Fukushima N, Kasai C, Tsukiyama K. Infrared photodissociation spectroscopy and density-functional calculations of protonated methanol cluster ions: Solvation structures of an excess proton. J Chem Phys 2008; 129:084304. [DOI: 10.1063/1.2963499] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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14
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Sakai D, Matsuda Y, Hachiya M, Mori M, Fujii A, Mikami N. Size-Selected Infrared Predissociation Spectroscopy of Neutral and Cationic Formamide−Water Clusters: Stepwise Growth of Hydrated Structures and Intracluster Hydrogen Transfer Induced by Vacuum-Ultraviolet Photoionization. J Phys Chem A 2008; 112:6840-9. [DOI: 10.1021/jp800743b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daichi Sakai
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Yoshiyuki Matsuda
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Masaki Hachiya
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Mayumi Mori
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai 980-8578, Japan
| | - Naohiko Mikami
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai 980-8578, Japan
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15
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Hachiya M, Matsuda Y, Suhara KI, Mikami N, Fujii A. Infrared predissociation spectroscopy of cluster cations of protic molecules, (NH[sub 3])[sub n]+], n=2–4 and (CH[sub 3]OH)[sub n]+], n=2,3. J Chem Phys 2008; 129:094306. [DOI: 10.1063/1.2971186] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Kuo JL, Fujii A, Mikami N. Theoretical Analyses of the Morphological Development of the Hydrogen Bond Network in Protonated Methanol Clusters. J Phys Chem A 2007; 111:9438-45. [PMID: 17685501 DOI: 10.1021/jp074676t] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Extensive density functional theory (DFT) calculations are carried out on various structural isomers of protonated methanol clusters, H(+)(MeOH)n (n = 2-9), to analyze the morphological development of the hydrogen bond network in the clusters with an increase of the cluster size. Coexistence of multiple structural isomers is demonstrated by the nearly degenerated energies. Moreover, significant temperature dependence of the preferential isomer structure is shown by the calculated Gibbs free energies. The previously reported infrared spectra of H(+)(MeOH)n (J. Phys. Chem. A 2005, 109, 138) are revisited on the basis of the spectral simulations of the isomers by DFT calculations.
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Affiliation(s)
- Jer-Lai Kuo
- School of Physical and Mathematical Sciences, Nanyang Technological University, 1 Nanyang Walk, Block 5, Level 3, Singapore 637616, Singapore.
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17
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Matsuda Y, Mori M, Hachiya M, Fujii A, Mikami N. Infrared predissociation spectroscopy of ammonia cluster cations (NH3)n+ (n=2–4) produced by vacuum-ultraviolet photoionization. J Chem Phys 2006; 125:164320. [PMID: 17092086 DOI: 10.1063/1.2360279] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Infrared predissociation spectroscopy of vacuum ultraviolet-pumped ion (IRPDS-VUV-PI) is performed on ammonia cluster cations (NH3)n+ (n=2-4) that are produced by VUV photoionization in supersonic jets. The structures of (NH3)2+ and (NH3)4+ are determined through the observation of infrared spectra and vibrational calculations based on ab initio calculations at the MP2/6-31G** and 6-31++G** levels. (NH3)2+ is found to be of the "hydrogen-transferred" form having the (H3N+-...NH2) composition. In contrast, (NH3)4+ exhibits the "head-to-head" dimer cation (H3...NH3+ core structure, where the positive charge is shared between two ammonia molecules in the core, and two other molecules are hydrogen bonded onto the core. An unequivocal assignment of the infrared spectrum of (NH3)3+ has not been achieved, because the presence of two isomeric structures could be suggested by the observed spectrum and theoretical calculations.
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Affiliation(s)
- Yoshiyuki Matsuda
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aoba, Aoba-ku, Sendai 980-8578, Japan.
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18
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Hu YJ, Fu HB, Bernstein ER. Infrared plus vacuum ultraviolet spectroscopy of neutral and ionic methanol monomers and clusters: New experimental results. J Chem Phys 2006; 125:154306. [PMID: 17059254 DOI: 10.1063/1.2357953] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
We present new observations of the infrared (IR) spectrum of neutral methanol and neutral and protonated methanol clusters employing IR plus vacuum ultraviolet (vuv) spectroscopic techniques. The tunable IR light covers the energy ranges of 2500-4500 cm(-1) and 5000-7500 cm(-1). The CH and OH fundamental stretch modes, the OH overtone mode, and combination bands are identified in the vibrational spectrum of supersonic expansion cooled methanol (2500-7500 cm(-1)). Cluster size selected IR plus vuv nonresonant infrared ion-dip infrared spectra of neutral methanol clusters, (CH(3)OH)(n) (n=2,[ellipsis (horizontal)],8), demonstrate that the methanol dimer has free and bonded OH stretch features, while clusters larger than the dimer display only hydrogen bonded OH stretch features. CH stretch mode spectra do not change with cluster size. These results suggest that all clusters larger than the dimer have a cyclic structure with OH groups involved in hydrogen bonding. CH groups are apparently not part of this cyclic binding network. Studies of protonated methanol cluster ions (CH(3)OH)(n)H(+) n=1,[ellipsis (horizontal)],7 are performed by size selected vuv plus IR photodissociation spectroscopy in the OH and CH stretch regions. Energies of the free and hydrogen bonded OH stretches exhibit blueshifts with increasing n, and these two modes converge to approximately 3670 and 3400 cm(-1) at cluster size n=7, respectively.
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Affiliation(s)
- Y J Hu
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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19
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Hu YJ, Fu HB, Bernstein ER. Infrared plus vacuum ultraviolet spectroscopy of neutral and ionic ethanol monomers and clusters. J Chem Phys 2006; 125:154305. [PMID: 17059253 DOI: 10.1063/1.2357952] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A high sensitivity spectroscopy is employed to detect vibrational antiitions of ethanol neutrals and ions in a supersonic expansion. The infrared (IR) features located at 3682 and 3667 cm(-1) can be assigned to the OH stretch for the two neutral C(2)H(5)OH conformers, anti and gauche, respectively. Their overtone energies located at 7179 (anti) and 7141 (gauche) cm(-1) are also identified. The OH fundamental stretch for ethanol ions is redshifted around 210 cm(-1), while the CH stretch modes are unchanged for neutral and ionic C(2)H(5)OH at around 2900-3000 cm(-1). The charge on the ethanol ion is apparently localized on the oxygen atom. IR induced photodissociation spectroscopy is applied to the study of neutral and protonated ethanol clusters. Neutral and protonated ethanol cluster vibrations are observed. The CH modes are not perturbed by the clustering process. Neutral clusters display only hydrogen bonded OH features, while the protonated ionic clusters display both hydrogen bonded and non-hydrogen-bonded features. These spectroscopic results are analyzed to obtain qualitative structural information on neutral and ionic ethanol clusters.
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Affiliation(s)
- Y J Hu
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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20
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Uras-Aytemiz N, Devlin JP, Sadlej J, Buch V. HCl Solvation at the Surface and within Methanol Clusters/Nanoparticles II: Evidence for Molecular Wires. J Phys Chem B 2006; 110:21751-63. [PMID: 17064136 DOI: 10.1021/jp062753z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Condensed-phase solvation of HCl on and within methanol nanoparticles was investigated by Fourier transform infrared (FTIR) spectroscopy, on-the-fly molecular dynamics as implemented in the density functional code Quickstep (which is part of the CP2K package), and ab initio calculations. Adsorption and solvation stages are identified and assigned with the help of calculated infrared spectra obtained from the simulations. The results have been further checked with MP2-level ab initio calculations. The range of acid solvation states extends from the single-coordinated slightly stretched HCl to proton-sharing with Zundel-like methanol O...H+...X- states, and finally to MeOH2+...Cl- units with full proton transfer. Furthermore, once the proton moves to methanol, it is mobilized along methanol molecular chains. Since the proton dynamics reflects the evolving local structures, the "proton" spectra display broad bands usually with underlying continua.
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Affiliation(s)
- Nevin Uras-Aytemiz
- Department of Chemistry, Suleyman Demirel University, 32260 Isparta, Turkey.
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Chang HC, Wu CC, Kuo JL. Recent advances in understanding the structures of medium-sized protonated water clusters. INT REV PHYS CHEM 2005. [DOI: 10.1080/01442350500448116] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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22
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Affiliation(s)
- Michael Meot-Ner
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
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Fujii A, Enomoto S, Miyazaki M, Mikami N. Morphology of Protonated Methanol Clusters: An Infrared Spectroscopic Study of Hydrogen Bond Networks of H+(CH3OH)n (n = 4−15). J Phys Chem A 2004; 109:138-41. [PMID: 16839098 DOI: 10.1021/jp0463464] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infrared spectroscopy of large-sized protonated methanol clusters, H(+)(MeOH)(n) (n = 4-15), was carried out in the OH stretch region to characterize the development of the hydrogen bond network with the cluster size, n. The band intensity of the free OH stretching mode decreased with n, and the band finally disappeared at n = 7. On the other hand, the broad absorption band due to hydrogen-bonded OH stretches exhibited a remarkable shift with the cluster size, and it finally converged on 3300 cm(-1) for n >/= approximately 10. The size dependence of the infrared spectra was morphologically interpreted in terms of the formation of the bicyclic hydrogen-bonded structure of the clusters.
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Affiliation(s)
- Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
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Hwang S, Chung DS. Density Functional Studies on the Solvation Free Energy of the Proton in Methanol. CHEM LETT 2002. [DOI: 10.1246/cl.2002.1220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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25
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Shi YJ, Consta S, Das AK, Mallik B, Lacey D, Lipson RH. A 118 nm vacuum ultraviolet laser/time-of-flight mass spectroscopic study of methanol and ethanol clusters in the vapor phase. J Chem Phys 2002. [DOI: 10.1063/1.1466467] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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26
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