1
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Kato T, Fujii A. Experimental confirmation of the Badger-Bauer rule in the protonated methanol clusters: weak hydrogen bond formation as a measure of terminal OH acidity in hydrogen bond networks. Phys Chem Chem Phys 2023; 25:30188-30192. [PMID: 37920966 DOI: 10.1039/d3cp04644c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
We report a linear correlation between the OH stretch frequency shift of the protonated methanol cluster, H+(MeOH)n, upon the π-hydrogen bond formation with benzene and the enthalpy change in clustering of H+(MeOH)n to H+(MeOH)n+1. This result suggests a new method to explore hydrogen bond strength in hydrogen bond networks.
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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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2
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Lei L, Yin J, Wu K, Yang N. Size-Dependent Electrochemistry of Oxygenated Ti 3 C 2 T x MXenes. SMALL METHODS 2023; 7:e2300302. [PMID: 36998117 DOI: 10.1002/smtd.202300302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Indexed: 06/09/2023]
Abstract
2D MXenes are widely proved to be potential electrode materials, although the size effect on their electrochemistry is not fully understood. In this work, Ti3 C2 Tx nanoflakes are prepared through acidic etching of Ti3 AlC2 powders, followed by the intercalation treatment with tetrapropylammonium hydroxide. Such a method produces large-scale delaminated and oxygenated nanoflakes. With aid of centrifugation, the nanoflakes with varied lateral sizes and thicknesses are collected, where electrochemical response of charged redox probes and polar phenol molecules is varied. Density functional theory and energy dispersive spectroscopy confirm such electrochemical response is dependent on the size and thickness of used nanoflakes, more exactly the oxygen content on their surface. Taking the nanoflakes obtained using a centrifugal speed of 5000 rpm (MX-TPA0.2 ) as an example, they feature good dispersibility, a high oxygen content, a small size, and a thin thickness. On these nanoflakes electrochemical response of polar p-substituted phenols is pronounced, stemming from a strong electron-withdrawing interaction of their oxygenated termination with the Ar-OH. A sensitive electrochemical sensor is further constructed for the detection of p-nitrophenol. This work thus provides an approach to synthesize MXenes with different sizes and thicknesses as well as further to reveal size-dependent electrochemistry of MXenes.
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Affiliation(s)
- Ling Lei
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Jiaxi Yin
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Kangbing Wu
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Nianjun Yang
- Department of Chemistry, Hasselt University, 3590, Diepenbeek, Belgium
- IMO-IMOMEC, Hasselt University, 3590, Diepenbeek, Belgium
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3
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Wortmann S, Kutta RJ, Nuernberger P. Monitoring the photochemistry of a formazan over 15 orders of magnitude in time. Front Chem 2022; 10:983342. [PMID: 36247663 PMCID: PMC9554553 DOI: 10.3389/fchem.2022.983342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
2,3,5-triphenyltetrazolium chloride (TTC) may convert into phenyl-benzo[c]tetrazolocinnolium chloride (PTC) and 1,3,5-triphenylformazan (TPF) under irradiation with light. The latter reaction, albeit enzymatically rather than photochemically, is used in so-called TTC assays indicating cellular respiration and cell growth. In this paper, we address the photochemistry of TPF with time-resolved spectroscopy on various time scales. TPF is stabilized by an intramolecular hydrogen bond and switches photochemically via an E-Z isomerization around an N=N double bond into another TPF-stereoisomer, from which further isomerizations around the C=N double bond of the phenylhydrazone group are possible. We investigate the underlying processes by time-resolved spectroscopy in dependence on excitation wavelength and solvent environment, resolving several intermediates over a temporal range spanning 15 orders of magnitude (hundreds of femtoseconds to hundreds of seconds) along the reaction path. In a quantum-chemical analysis, we identify 16 stable ground-state isomers and discuss which ones are identified in the experimental data. We derive a detailed scheme how these species are thermally and photochemically interconnected and conclude that proton transfer processes are involved.
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4
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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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5
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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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6
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Lin CK, Huang QR, Li YC, Nguyen HQ, Kuo JL, Fujii A. Anharmonic Coupling Revealed by the Vibrational Spectra of Solvated Protonated Methanol: Fermi Resonance, Combination Bands, and Isotope Effect. J Phys Chem A 2021; 125:1910-1918. [PMID: 33636081 DOI: 10.1021/acs.jpca.1c00068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Intriguing vibrational features of solvated protonated methanol between 2400-3800 cm-1 are recorded by infrared predissociation spectroscopy. Positions of absorption bands corresponding to OH stretching modes are sensitive to changes in solvation environments, thus leading to changes in these vibrational features. Two anharmonic coupling mechanisms, Fermi resonance (FR) contributed by bending overtones and combination band (CB) associated with intermolecular stretching modes, are known to lead to band splitting of OH stretching fundamentals in solvated hydronium and ammonium. Theoretical analyses based on the ab initio anharmonic algorithm not only well reproduce the experimentally observed features but also elucidate the magnitudes of such couplings and the resulting interplay between these two mechanisms, which provide convincing assignments of the spectral patterns. Moreover, while the hydroxyl group plays the leading role in all the above-mentioned features, the role of the methyl group is also analyzed. Through the H/D isotope substitution, we identify overtones of the methyl-hydroxyl rocking modes and their participation in FR.
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Affiliation(s)
- Chih-Kai Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10617, ROC
| | - Qian-Rui Huang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10617, ROC
| | - Ying-Cheng Li
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10617, ROC
| | - Ha-Quyen Nguyen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10617, ROC
| | - Jer-Lai Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10617, ROC
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
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7
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Nastase SAF, Cnudde P, Vanduyfhuys L, De Wispelaere K, Van Speybroeck V, Catlow CRA, Logsdail AJ. Mechanistic Insight into the Framework Methylation of H-ZSM-5 for Varying Methanol Loadings and Si/Al Ratios Using First-Principles Molecular Dynamics Simulations. ACS Catal 2020; 10:8904-8915. [PMID: 32923027 PMCID: PMC7479850 DOI: 10.1021/acscatal.0c01454] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/08/2020] [Indexed: 11/29/2022]
Abstract
![]()
The
methanol-to-hydrocarbon process is known to proceed autocatalytically
in H-ZSM-5 after an induction period where framework methoxy species
are formed. In this work, we provide mechanistic insight into the
framework methylation within H-ZSM-5 at high methanol loadings and
varying acid site densities by means of first-principles molecular
dynamics simulations. The molecular dynamics simulations show that
stable methanol clusters form in the zeolite pores, and these clusters
commonly deprotonate the active site; however, the cluster size is
dependent on the temperature and acid site density. Enhanced sampling
molecular dynamics simulations give evidence that the barrier for
methanol conversion is significantly affected by the neighborhood
of an additional acid site, suggesting that cooperative effects influence
methanol clustering and reactivity. The insights obtained are important
steps in optimizing the catalyst and engineering the induction period
of the methanol-to-hydrocarbon process.
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Affiliation(s)
- Stefan A. F. Nastase
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
| | - Pieter Cnudde
- Center for Molecular Modeling, Ghent University, Zwijnaarde, Ghent 9000, Belgium
| | - Louis Vanduyfhuys
- Center for Molecular Modeling, Ghent University, Zwijnaarde, Ghent 9000, Belgium
| | | | | | - C. Richard A. Catlow
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
- Department of Chemistry, University College London, 20 Gordon Street, London WC1E 6BT, U.K
- UK Catalysis Hub, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Oxford OX11 0FA, U.K
| | - Andrew J. Logsdail
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
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8
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Long Z, Atsango AO, Napoli JA, Markland TE, Tuckerman ME. Elucidating the Proton Transport Pathways in Liquid Imidazole with First-Principles Molecular Dynamics. J Phys Chem Lett 2020; 11:6156-6163. [PMID: 32633523 DOI: 10.1021/acs.jpclett.0c01744] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Imidazole is a promising anhydrous proton conductor with a high conductivity comparable to that of water at a similar temperature relative to its melting point. Previous theoretical studies of the mechanism of proton transport in imidazole have relied either on empirical models or on ab initio trajectories that have been too short to draw significant conclusions. Here, we present the results of multiple time-step ab initio molecular dynamics simulations of an excess proton in liquid imidazole reaching 1 ns in total simulation time. We find that the proton transport is dominated by structural diffusion, with the diffusion constant of the proton defect being ∼8 times higher than that of self-diffusion of the imidazole molecules. By using correlation function analysis, we decompose the mechanism for proton transport into a series of first-order processes and show that the proton transport mechanism occurs over three distinct time and length scales. Although the mechanism at intermediate times is dominated by hopping along pseudo-one-dimensional chains, at longer times the overall rate of diffusion is limited by the re-formation of these chains. These results provide a more complete picture of the traditional idealized Grotthuss structural diffusion mechanism.
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Affiliation(s)
- Zhuoran Long
- Department of Chemistry, New York University, New York, New York 10003, United States
| | - Austin O Atsango
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Joseph A Napoli
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Thomas E Markland
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Mark E Tuckerman
- Department of Chemistry, New York University, New York, New York 10003, United States
- Courant Institute of Mathematical Science, New York University, New York, New York 10012, United States
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China
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9
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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: 8] [Impact Index Per Article: 1.3] [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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10
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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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11
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Katada M, Hsu PJ, Fujii A, Kuo JL. Temperature and Size Dependence of Characteristic Hydrogen-Bonded Network Structures with Ion Core Switching in Protonated (Methanol)6–10–(Water)1 Mixed Clusters: A Revisit. J Phys Chem A 2017; 121:5399-5413. [DOI: 10.1021/acs.jpca.7b03762] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marusu Katada
- 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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12
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Lee YM, Park SY, Kim H, Kim TG, Kwon OH. Photoinduced strong acid–weak base reactions in a polar aprotic solvent. Methods Appl Fluoresc 2016; 4:024004. [DOI: 10.1088/2050-6120/4/2/024004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Park SY, Lee YM, Kwac K, Jung Y, Kwon OH. Alcohol Dimer is Requisite to Form an Alkyl Oxonium Ion in the Proton Transfer of a Strong (Photo)Acid to Alcohol. Chemistry 2016; 22:4340-4. [DOI: 10.1002/chem.201503948] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Sun-Young Park
- Center for Soft and Living Matter; Institute for Basic Science (IBS); Ulsan 689-798 Republic of Korea
| | - Young Min Lee
- Department of Chemistry; Ulsan National Institute of Science and Technology (UNIST); Ulsan 689-798 Republic of Korea
| | - Kijeong Kwac
- Graduate School of Energy, Environment, Water and Sustainability (EEWS); Korea Advanced Institute of Science and Technology (KAIST); Daejeon 305-701 Republic of Korea
| | - Yousung Jung
- Graduate School of Energy, Environment, Water and Sustainability (EEWS); Korea Advanced Institute of Science and Technology (KAIST); Daejeon 305-701 Republic of Korea
| | - Oh-Hoon Kwon
- Center for Soft and Living Matter; Institute for Basic Science (IBS); Ulsan 689-798 Republic of Korea
- Department of Chemistry; Ulsan National Institute of Science and Technology (UNIST); Ulsan 689-798 Republic of Korea
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14
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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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15
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Abu-samha M, Børve KJ. HCl dissociation in methanol clusters from ab initio molecular dynamics simulations and inner-shell photoelectron spectroscopy. J Phys Chem A 2014; 118:6900-7. [PMID: 25079917 DOI: 10.1021/jp504883r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
HCl dissociation in methanol clusters is studied by ab initio molecular dynamics simulations and experimentally by X-ray photoelectron spectroscopy. From theoretical simulations of HCl in oligomers and medium-sized clusters of methanol, two states of solvation are identified for HCl: an intermediate proton-sharing (ion pair) state and a fully dissociated state. Lowering the temperature from 150 to 100 K is found to promote full dissociation over the proton-sharing state. The dissociation of HCl is well reflected in the experimental chlorine 2p photoelectron spectrum recorded for a beam of clusters formed by adiabatic expansion of the vapor over a solution of HCl in methanol. In order to reproduce the observed Cl 2p spectrum by means of theoretical line-shape modeling, one needs to take into account both the intermediate proton-sharing state and the fully dissociated state.
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Affiliation(s)
- Mahmoud Abu-samha
- Department of Chemistry, University of Bergen , Allégaten 41, NO-5007 Bergen, Norway
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16
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Douvris C, Michl J. Update 1 of:Chemistry of the Carba-closo-dodecaborate(−) Anion, CB11H12–. Chem Rev 2014; 113:PR179-233. [PMID: 23944158 DOI: 10.1021/cr400059k] [Citation(s) in RCA: 159] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christos Douvris
- Institute of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic, 16610 Prague, Czech Republic
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Josef Michl
- Institute of Organic Chemistry and Biochemistry, Academy of Science of the Czech Republic, 16610 Prague, Czech Republic
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
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17
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Maiorov VD, Kislina IS, Rykounov AA, Vener MV. The structure and vibrational features of proton disolvates in water-ethanol solutions of HCl: the combined spectroscopic and theoretical study. J PHYS ORG CHEM 2013. [DOI: 10.1002/poc.3251] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Vladimir D. Maiorov
- Semenov Institute of Chemical Physics; Russian Academy of Sciences; Moscow Russia
| | - Irina S. Kislina
- Semenov Institute of Chemical Physics; Russian Academy of Sciences; Moscow Russia
| | - Alexey A. Rykounov
- Snezhinsk Physics and Technology Institute; National Research Nuclear University MEPhI; Snezhinsk Russia
| | - Mikhail V. Vener
- Quantum Chemistry Department; Mendeleev University of Chemical Technology; Moscow Russia
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18
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Abstract
Recent research has taught us that most protonated species are decidedly not well represented by a simple proton addition. What is the actual nature of the hydrogen ion (the "proton") when H(+), HA, H2A(+), and so forth are written in formulas, chemical equations, and acid catalyzed reactions? In condensed media, H(+) must be solvated and is nearly always dicoordinate, as illustrated by isolable bisdiethyletherate salts having H(OEt2)2(+) cations and weakly coordinating anions. Even carbocations such as protonated alkenes have significant C-H···anion hydrogen bonding that gives the active protons two-coordinate character. Hydrogen bonding is everywhere, particularly when acids are involved. In contrast to the normal, asymmetric O-H···O hydrogen bonding found in water, ice, and proteins, short, strong, low-barrier (SSLB) H-bonding commonly appears when strong acids are present. Unusually low frequency IR νOHO bands are a good indicator of SSLB H-bonds, and curiously, bands associated with group vibrations near H(+) in low-barrier H-bonding often disappear from the IR spectrum. Writing H3O(+) (the Eigen ion), as often appears in textbooks, might seem more realistic than H(+) for an ionized acid in water. However, this, too, is an unrealistic description of H(aq)(+). The dihydrated H(+) in the H5O2(+) cation (the Zundel ion) gets somewhat closer but still fails to rationalize all the experimental and computational data on H(aq)(+). Researchers do not understand the broad swath of IR absorption from H(aq)(+), known as the "continuous broad absorption" (cba). Theory has not reproduced the cba, but it appears to be the signature of delocalized protons whose motion is faster than the IR time scale. What does this mean for reaction mechanisms involving H(aq)(+)? For the past decade, the carborane acid H(CHB11Cl11) has been the strongest known Brønsted acid. (It is now surpassed by the fluorinated analogue H(CHB11F11).) Carborane acids are strong enough to protonate alkanes at room temperature, giving H2 and carbocations. They protonate chloroalkanes to give dialkylchloronium ions, which decay to carbocations. By partially protonating an oxonium cation, they get as close to the fabled H4O(2+) ion as can be achieved outside of a computer.
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Affiliation(s)
- Christopher A. Reed
- Department of Chemistry, University of California, Riverside, California 92521, USA
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Stoyanov ES, Stoyanova IV, Tham FS, Reed CA. Evidence for CH Hydrogen Bonding in Salts of tert-Butyl Cation. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201203958] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Stoyanov ES, Stoyanova IV, Tham FS, Reed CA. Evidence for C-H hydrogen bonding in salts of tert-butyl cation. Angew Chem Int Ed Engl 2012; 51:9149-51. [PMID: 22887067 DOI: 10.1002/anie.201203958] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Indexed: 11/10/2022]
Abstract
Environmentally sensitive: A combination of C-H anion hydrogen bonding and hyperconjugative charge delocalization explains the sensitivity of the IR spectrum of the tert-butyl cation to its anion (see high-resolution X-ray structure with a CHB(11)Cl(11)(-) counterion). The νCH vibration of the cation scales linearly with the basicity of carborane anions on the νNH scale. The same also holds for the C(6)H(7)(+) benzenium ion.
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Affiliation(s)
- Evgenii S Stoyanov
- Center for S&P Block Chemistry, Department of Chemistry, University of California, Riverside, CA 92521, USA.
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Stoyanov ES, Gunbas G, Hafezi N, Mascal M, Stoyanova IV, Tham FS, Reed CA. The R3O+···H+ hydrogen bond: toward a tetracoordinate oxadionium(2+) ion. J Am Chem Soc 2011; 134:707-14. [PMID: 22133059 DOI: 10.1021/ja209942s] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxatriquinanes are tricyclic oxonium ions which are known to possess remarkable solvolytic stability compared to simple alkyl oxonium salts. Their rigid, hemispherical structure presents an oxygen at the apex of three fused five-membered rings. While trivalent oxygen species like these have been well described in the literature, the ability of oxygen to enter into a fourth covalent bonding relationship has been visited in theory and suggested by the outcome of certain reactions conducted in superacidic media, but has never been established by the characterization of a stable, persistent R(3)OH(2+) or R(4)O(2+) ion. In this study, the nucleophilicity of the oxatriquinane oxygen was evaluated first by a series of protonation studies using the Brønsted superacid H(CHB(11)Cl(11)) both in the solid state and in liquid HCl solution. The interaction of the oxatriquinane oxygen with a bridging carbocation was also examined. A strong case could be made for the occurrence of hydrogen bonding between H(CHB(11)Cl(11)) and oxatriquinane using IR spectroscopy. Under the most forcing protonation conditions, the oxatriquinane ring is cleaved to give a bridged, dicationic, protonated tetrahydrofuran-carbenium ion.
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Affiliation(s)
- Evgenii S Stoyanov
- Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, California 92521-0403, USA.
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Beran GJO, Chronister EL, Daemen LL, Moehlig AR, Mueller LJ, Oomens J, Rice A, Santiago-Dieppa DR, Tham FS, Theel K, Yaghmaei S, Morton TH. Vibrations of a chelated proton in a protonated tertiary diamine. Phys Chem Chem Phys 2011; 13:20380-92. [DOI: 10.1039/c1cp22065a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Longas MO, Cheairs K, Puchalski MM, Park JI. Reliability of fourier transform infrared spectroscopy in the characterization of human skin. ACTA ACUST UNITED AC 2011. [DOI: 10.4236/abc.2011.12004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Min SK, Park M, Singh NJ, Lee HM, Lee EC, Kim KS, Lagutschenkov A, Niedner-Schatteburg G. Chiral transformation in protonated and deprotonated adipic acids through multistep internal proton transfer. Chemistry 2010; 16:10373-9. [PMID: 20652911 DOI: 10.1002/chem.200903355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Protonated and deprotonated adipic acids (PAA: HOOC-(CH(2))(4)--COOH(2) (+) and DAA: HOOC-(CH(2))(4)-COO(-)) have a charged hydrogen bond under the influence of steric constraint due to the molecular skeleton of a circular ring. Despite the similarity between PAA and DAA, it is surprising that the lowest energy structure of PAA is predicted to have (H(2)O...H...OH(2))(+) Zundel-like symmetric hydrogen bonding, whereas that of DAA has H(3)O(+) Eigen-like asymmetric hydrogen bonding. The energy profiles show that direct proton transfer between mirror image structures is unfavorable. Instead, the chiral transformation is possible by subsequent backbone twistings through stepwise proton transfer along multistep intermediate structures, which are Zundel-like ions for PAA and Eigen-like ions for DAA. This type of chiral transformation by multistep intramolecular proton transfers is unprecedented. Several prominent OH...O short hydrogen-bond stretching peaks are predicted in the range of 1000-1700 cm(-1) in the Car-Parrinello molecular dynamics (CPMD) simulations, which show distinctive signatures different from ordinary hydrogen-bond peaks. The O-H-O stretching peaks in the range of 1800-2700 cm(-1) become insignificant above around 150 K and are almost washed out at about 300 K.
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Affiliation(s)
- Seung Kyu Min
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, 790-784 Pohang, South Korea
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Bing D, Hamashima T, Fujii A, Kuo JL. Anticooperative Effect Induced by Mixed Solvation in H+(CH3OH)m(H2O)n (m + n = 5 and 6): A Theoretical and Infrared Spectroscopic Study. J Phys Chem A 2010; 114:8170-7. [DOI: 10.1021/jp104931t] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Dan Bing
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan, and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Toru Hamashima
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan, and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Asuka Fujii
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan, and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Jer-Lai Kuo
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore, Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan, and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
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Prakash M, Subramanian V, Gadre SR. Stepwise Hydration of Protonated Carbonic Acid: A Theoretical Study. J Phys Chem A 2009; 113:12260-75. [DOI: 10.1021/jp904576u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. Prakash
- Chemical Laboratory, Central Leather Research Institute, Central Leather Research Institute, Adyar, Chennai 600 020, India, and Department of Chemistry, University of Pune, Pune 411 007, India
| | - V. Subramanian
- Chemical Laboratory, Central Leather Research Institute, Central Leather Research Institute, Adyar, Chennai 600 020, India, and Department of Chemistry, University of Pune, Pune 411 007, India
| | - Shridhar R. Gadre
- Chemical Laboratory, Central Leather Research Institute, Central Leather Research Institute, Adyar, Chennai 600 020, India, and Department of Chemistry, University of Pune, Pune 411 007, India
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Bing D, Kuo JL, Suhara KI, Fujii A, Mikami N. Proton Switch Correlated with the Morphological Development of the Hydrogen-Bond Network in H+(MeOH)m(H2O)1 (m = 1−9): A Theoretical and Infrared Spectroscopic Study. J Phys Chem A 2009; 113:2323-32. [DOI: 10.1021/jp900066u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Stoyanov ES, Stoyanova IV, Tham FS, Reed CA. The nature of the hydrated proton H(aq)+ in organic solvents. J Am Chem Soc 2008; 130:12128-38. [PMID: 18700768 DOI: 10.1021/ja803535s] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nature of H(H2O)n(+) cations for n = 3-8 with weakly basic carborane counterions has been studied by IR spectroscopy in benzene and dichloroethane solution. Contrary to general expectation, neither Eigen-type H3O x 3 H2O(+) nor Zundel-type H5O2(+) x 4 H2O ions are present. Rather, the core species is the H7O3(+) ion.
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Affiliation(s)
- Evgenii S Stoyanov
- Department of Chemistry, University of California, Riverside, California 92521, USA.
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