1
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Tachikawa H. Mechanism of ionic dissociation of HCl in the smallest water clusters. Phys Chem Chem Phys 2024; 26:3623-3631. [PMID: 38224187 DOI: 10.1039/d3cp05715a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
The dissociation of strong acids into water is a fundamental process in chemistry and biology. Determining the minimum number of water molecules that can result in an ionic dissociation of hydrochloric acid (HCl → H+ + Cl-) remains a challenging subject. In this study, the reactions of H2O with HCl(H2O)n-1 (HCl-H2O cluster), i.e., HCl(H2O)n-1 + H2O (n = 3-7), were investigated by using the direct ab initio molecular dynamics (AIMD) method. Direct AIMD calculations were performed to set the collision energy of H2O to zero for all trajectories. For n = 3, no reaction occurred. In contrast, HCl dissociated to H+ + Cl- at n = 4, forming a contact ion pair (cIP) and solvent-separated ion pair (ssIP) as products. The reactions were expressed as HCl(H2O)3 + H2O → H3O+(H2O)2Cl- (ssIP), and HCl(H2O)3 + H2O → H3O+(Cl-)(H2O)2 (cIP). The ion pair (IP) products were dependent on the collision site of H2O relative to HCl(H2O)3. For n = 5-7, both IPs were formed through the reaction between H2O and HCl(H2O)n-1 (n = 5-7). The reaction between HCl and (H2O)4 (HCl + (H2O)4 → HCl(H2O)4) was non-reactive in IP formation. The reaction mechanism was discussed based on the theoretical results.
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Affiliation(s)
- Hiroto Tachikawa
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
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2
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Golikov O, Yerezhep D, Akylbayeva A, Sokolov DY, Korshikov E, Nurmukan A, Aldiyarov A. Cryovacuum setup for optical studies of astrophysical ice. Sci Rep 2023; 13:21155. [PMID: 38036724 PMCID: PMC10689453 DOI: 10.1038/s41598-023-48541-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/28/2023] [Indexed: 12/02/2023] Open
Abstract
This paper presents a cryovacuum setup for the study of substances under near-space conditions. The setup makes it possible to study the infrared spectra, refractive index, and density of substances that are condensed from the vapor phase onto a cooled substrate in the temperature range from 11 to 300 K. At the same time, it is possible to obtain the ultimate pressure of 1 × 10-10 Torr in the vacuum chamber. The presented setup is based on FTIR spectroscopy (the spectral measurement range is 400-7800 cm-1) and laser interference, through which the important physical and optical parameters are determined. A number of experiments allow us to point out that the data obtained using this setup correlate well with the experiments of other authors. Due to the non-directional deposition of substances from the vapor phase, the ice formed resembles the one formed under cosmic conditions as closely as possible, which makes the presented setup particularly valuable. The presented cryovacuum setup can be used for the interpretation of data obtained during astrophysical observations, providing a means to determine the properties of cosmic objects.
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Affiliation(s)
- Oleg Golikov
- Al-Farabi Kazakh National University, Al-Farabi Av., 71, 050040, Almaty, Kazakhstan
| | - Darkhan Yerezhep
- Al-Farabi Kazakh National University, Al-Farabi Av., 71, 050040, Almaty, Kazakhstan.
- Satbayev University, Satbaev str., 22, 050040, Almaty, Kazakhstan.
- Institute of Physics and Technology, Satbayev University, Ibragimov str., 11, 050032, Almaty, Kazakhstan.
| | - Aigerim Akylbayeva
- Al-Farabi Kazakh National University, Al-Farabi Av., 71, 050040, Almaty, Kazakhstan
- Satbayev University, Satbaev str., 22, 050040, Almaty, Kazakhstan
| | - Dmitriy Yurievich Sokolov
- Al-Farabi Kazakh National University, Al-Farabi Av., 71, 050040, Almaty, Kazakhstan
- Almaty Technological University, Tole Bi av., 100, 050012, Almaty, Kazakhstan
| | - Eugeniy Korshikov
- Al-Farabi Kazakh National University, Al-Farabi Av., 71, 050040, Almaty, Kazakhstan
| | - Assel Nurmukan
- Al-Farabi Kazakh National University, Al-Farabi Av., 71, 050040, Almaty, Kazakhstan
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3
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Li W, Pérez C, Steber AL, Schnell M, Lv D, Wang G, Zeng X, Zhou M. Evolution of Solute-Water Interactions in the Benzaldehyde-(H 2O) 1-6 Clusters by Rotational Spectroscopy. J Am Chem Soc 2023; 145:4119-4128. [PMID: 36762446 DOI: 10.1021/jacs.2c11732] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The investigation on the preferred arrangement and intermolecular interactions of gas phase solute-water clusters gives insights into the intermolecular potentials that govern the structure and dynamics of the aqueous solutions. Here, we report the investigation of hydrated coordination networks of benzaldehyde-(water)n (n = 1-6) clusters in a pulsed supersonic expansion using broadband rotational spectroscopy. Benzaldehyde (PhCHO) is the simplest aromatic aldehyde that involves both hydrophilic (CHO) and hydrophobic (phenyl ring) functional groups, which can mimic molecules of biological significance. For the n = 1-3 clusters, the water molecules are connected around the hydrophilic CHO moiety of benzaldehyde through a strong CO···HO hydrogen bond and weak CH···OH hydrogen bond(s). For the larger clusters, the spectra are consistent with the structures in which the water clusters are coordinated on the surface of PhCHO with both the hydrophilic CHO and hydrophobic phenyl ring groups being involved in the bonding interactions. The presence of benzaldehyde does not strongly interfere with the cyclic water tetramer and pentamer, which retain the same structure as in the pure water cluster. The book isomer instead of cage or prism isomers of the water hexamer is incorporated into the microsolvated cluster. The PhCHO molecule deviates from the planar structure upon sequential addition of water molecules. The PhCHO-(H2O)1-6 clusters may serve as a simple model system in understanding the solute-water interactions of biologically relevant molecules in an aqueous environment.
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Affiliation(s)
- Weixing Li
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Songhu Rd. 2005, 200438 Shanghai, China
| | - Cristóbal Pérez
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Amanda L Steber
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Melanie Schnell
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- Christian-Albrechts-Universität zu Kiel, Institute of Physical Chemistry, Max-Eyth-Str. 1, 24118 Kiel, Germany
| | - Dingding Lv
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Songhu Rd. 2005, 200438 Shanghai, China
| | - Guanjun Wang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Songhu Rd. 2005, 200438 Shanghai, China
| | - Xiaoqing Zeng
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Songhu Rd. 2005, 200438 Shanghai, China
| | - Mingfei Zhou
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Songhu Rd. 2005, 200438 Shanghai, China
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4
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Ventura E, Bezerra MG, Leitão EFV, do Monte SA. Acid Enriched with Methanol: Formation of a Prebiotic Cluster in the Interstellar Medium. Chemphyschem 2022; 23:e202200403. [PMID: 35962978 DOI: 10.1002/cphc.202200403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/12/2022] [Indexed: 11/12/2022]
Abstract
Organic molecules are a potential source of prebiotic chemistry in the interstellar medium (ISM). Methanol (MetOH) is a very important source of more complex molecules. H 3 O + (aq) and Cl - (aq) are fundamental to living organisms and can be generated in the ISM from the dissociation of HCl with just four water molecules, yielding the (H 3 O) + (H 2 O) 3 Cl - ion-pair. Here, a detailed mechanism, based on density functional theory (DFT) and ab-initio (2 nd order Mfller-Plesset perturbation theory, MP2) calculations, is suggested for the substitution reactions of these water molecules by MetOH. The time required for formation of an appreciable amount of the product ((H 3 O) + (MetOH) 3 Cl - ) can be only few years. Such reaction can take place in Sagittarius B2, where HCl, H 2 O and MetOH have already been identified and it can be an important source for the formation of more complex prebiotic structures.
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Affiliation(s)
- Elizete Ventura
- Universidade Federal da Paraiba, Departamento de Química, Centro de Ciências Exatas e da Natureza, 58-059-900, Joao Pessoa, BRAZIL
| | - Mariana Guedes Bezerra
- Universidade Federal da Paraiba, Departamento de Química, Centro de Ciências Exatas e da Natureza - Campus I, 58-059-900, Joao Pessoa, BRAZIL
| | - Ezequiel Fragoso Vieira Leitão
- Universidade Federal de Campina Grande, Unidade Acadêmica de Ciências Exatas e da Natureza, 58900-000, Cajazeiras, BRAZIL
| | - Silmar Andrade do Monte
- Universidade Federal da Paraiba, Quimica, Departamento de Quimica, CCEN,, Cidade Universitaria - Campus I, 58059-900, Joao Pessoa, BRAZIL
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5
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Mani D, Roy TK, Khatri J, Schwaab G, Blach S, Hölzl C, Forbert H, Marx D, Havenith M. Internal Electric Field-Induced Formation of Exotic Linear Acetonitrile Chains. J Phys Chem Lett 2022; 13:6852-6858. [PMID: 35861316 DOI: 10.1021/acs.jpclett.2c01482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The application of external electric and magnetic fields is a powerful tool for aligning molecules in a controlled way, if the thermal fluctuations are small. Here we demonstrate that the same holds for internal electric fields in a molecular cluster. The electric field of a single molecular dipole, HCl, is used to manipulate the aggregation mechanism of subsequently added acetonitrile molecules. As a result, we could form exotic linear acetonitrile (CH3CN) chains at 0.37 K, as confirmed by infrared spectroscopy in superfluid helium nanodroplets. These linear chains are not observed in the absence of HCl and can be observed only when the internal electric field created by an HCl molecule is present. The accompanying simulations provide mechanistic insights into steric control, explain the selectivity of the process, and show that non-additive electronic polarization effects systematically enhance the dipole moment of these linear chains. Thus, adding more CH3CN monomers even supports further quasi-linear chain growth.
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Affiliation(s)
- Devendra Mani
- Department of Chemistry, Indian Institute of Technology Kanpur, 208016 Kanpur, India
| | - Tarun Kumar Roy
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Jai Khatri
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Sebastian Blach
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Christoph Hölzl
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Harald Forbert
- Center for Solvation Science ZEMOS, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
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6
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Schwaab G, Pérez de Tudela R, Mani D, Pal N, Roy TK, Gabas F, Conte R, Durán Caballero L, Ceotto M, Marx D, Havenith M. Zwitter Ionization of Glycine at Outer Space Conditions due to Microhydration by Six Water Molecules. PHYSICAL REVIEW LETTERS 2022; 128:033001. [PMID: 35119904 DOI: 10.1103/physrevlett.128.033001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 08/09/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
We investigate glycine microsolvation with water molecules, mimicking astrophysical conditions, in our laboratory by embedding these clusters in helium nanodroplets at 0.37 K. We recorded mass selective infrared spectra in the frequency range 1500-1800 cm^{-1} where two bands centered at 1630 and 1724 cm^{-1} were observed. By comparison with the extensive accompanying calculations, the band at 1630 cm^{-1} was assigned to the COO^{-} asymmetric stretching mode of the zwitter ion and the band at 1724 cm^{-1} was assigned to redshifted C=O stretch within neutral clusters. We show that zwitter ion formation of amino acids readily occurs with only few water molecules available even under extreme conditions.
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Affiliation(s)
- Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | | | - Devendra Mani
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh 208016, India
| | - Nitish Pal
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Tarun Kumar Roy
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Fabio Gabas
- Dipartimento di Chimica, Università degli Studi di Milano, 20133 Milano, Italy
| | - Riccardo Conte
- Dipartimento di Chimica, Università degli Studi di Milano, 20133 Milano, Italy
| | | | - Michele Ceotto
- Dipartimento di Chimica, Università degli Studi di Milano, 20133 Milano, Italy
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
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7
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Zech A, Head-Gordon M. Dissociation of HCl in water nanoclusters: an energy decomposition analysis perspective. Phys Chem Chem Phys 2021; 23:26737-26749. [PMID: 34846396 DOI: 10.1039/d1cp04587c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As known, small HCl-water nanoclusters display a particular dissociation behaviour, whereby at least four water molecules are required for the ionic dissociation of HCl. In this work, we examine how intermolecular interactions promote the ionic dissociation of such nanoclusters. To this end, a set of 45 HCl-water nanoclusters with up to four water molecules is introduced. Energy decomposition analysis based on absolutely localized molecular orbitals (ALMO-EDA) is employed in order to study the importance of frozen interaction, dispersion, polarization, and charge-transfer for the dissociation. The vertical ALMO-EDA scheme is applied to HCl-water clusters along a proton-transfer coordinate varying the amount of spectator water molecules. The corresponding ALMO-EDA results show a clear preference for the dissociated cluster only in the presence of four water molecules. Our analysis of adiabatic ALMO-EDA results reveals a push-pull mechanism for the destabilization of the HCl bond based on the synergy between forward and backward charge-transfer.
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Affiliation(s)
- Alexander Zech
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, USA.
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, USA. .,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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8
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Roy TK, Mani D, Schwaab G, Havenith M. An infrared spectroscopic study of trifluoromethoxybenzene⋯methanol complexes formed in superfluid helium nanodroplets. Phys Chem Chem Phys 2021; 23:25180-25187. [PMID: 34730133 DOI: 10.1039/d1cp03136h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have studied the intermolecular complex formation between trifluoromethoxybenzene and methanol (CD3OD) in superfluid helium droplets by infrared spectroscopy in the spectral range of 2630-2730 cm-1, covering the O-D stretches of methanol-d4 (CD3OD). The cluster size associated with the observed bands is deduced from the variation of infrared intensity of a particular band with the partial pressures of trifluoromethoxybenzene and methanol. Quantum chemical calculations are performed at the MP2/6-311++G(d,p) level of theory to complement the experimental results. As a result, we have identified six different conformers of the trifluoromethoxybenzene⋯methanol intermolecular complex: three bound via O-H⋯O hydrogen bonds and the other three via O-H⋯π hydrogen bonds. Furthermore, to access the effect of fluorination on the methyl unit of anisole molecules, we compare the IR spectrum of trifluoromethoxybenzene (C6H5OCF3)⋯methanol with our earlier reported spectrum of anisole (C6H5OCH3)⋯methanol.
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Affiliation(s)
- Tarun Kumar Roy
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany.
| | - Devendra Mani
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh 208016, India.
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany.
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, Bochum 44780, Germany.
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9
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Abstract
Cooperative or nonadditive effects contribute to the pairwise noncovalent interaction of two molecules in a cluster or the condensed phase in ways that depend on the specific arrangements and interactions of the other surrounding molecules that constitute their environment. General expressions for an effective two-body interaction are presented, which are correct to increasing orders in the many-body expansion. The simplest result, correct through third order, requires only seven individual calculations, in contrast to a linear number of three-body contributions. Two applications are presented. First, an error analysis is performed on a model (H2O)8 cluster which completes the first solvation shell of a central water-water hydrogen bond. Energy decomposition analysis is performed to show that the largest effects of cooperativity on the central hydrogen bond arise from electrical polarization. Second, the nature of cooperative effects on proton transfer in an HCl + (H2O)4 cluster is characterized.
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Affiliation(s)
- Cameron Mackie
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Alexander Zech
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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10
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Tripathi R, Durán Caballero L, Pérez de Tudela R, Hölzl C, Marx D. Unveiling Zwitterionization of Glycine in the Microhydration Limit. ACS OMEGA 2021; 6:12676-12683. [PMID: 34056419 PMCID: PMC8154221 DOI: 10.1021/acsomega.1c00869] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
Charge separation under solvation stress conditions is a fundamental process that comes in many forms in doped water clusters. Yet, the mechanism of intramolecular charge separation, where constraints due to the molecular structure might be intricately tied to restricted solvation structures, remains largely unexplored. Microhydrated amino acids are such paradigmatic molecules. Ab initio simulations are carried out at 300 K in the frameworks of metadynamics sampling and thermodynamic integration to map the thermal mechanisms of zwitterionization using Gly(H2O) n with n = 4 and 10. In both cases, a similar water-mediated proton transfer chain mechanism is observed; yet, detailed analyses of thermodynamics and kinetics demonstrate that the charge-separated zwitterion is the preferred species only for n = 10 mainly due to kinetic stabilization. Structural analyses disclose that bifurcated H-bonded water bridges, connecting the cationic and anionic sites in the fluctuating microhydration network at room temperature, are enhanced in the transition-state ensemble exclusively for n = 10 and become overwhelmingly abundant in the stable zwitterion. The findings offer potential insights into charge separation under solvation stress conditions beyond the present example.
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11
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Pérez de Tudela R, Marx D. Generating Excess Protons in Microsolvated Acid Clusters under Ambient Conditions: An Issue of Configurational Entropy versus Internal Energy. Chemistry 2020; 26:11955-11959. [PMID: 32080914 PMCID: PMC7540491 DOI: 10.1002/chem.202000864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Indexed: 11/29/2022]
Abstract
Acid dissociation, and thus liberation of excess protons in small water droplets, impacts on diverse fields such as interstellar, atmospheric or environmental chemistry. At cryogenic temperatures below 1 K, it is now well established that as few as four water molecules suffice to dissociate the generic strong acid HCl, yet temperature-driven recombination sets in simply upon heating that cluster. Here, the fundamental question is posed of how many more water molecules are required to stabilize a hydrated excess proton at room temperature. Ab initio path integral simulations disclose that not five, but six water molecules are needed at 300 K to allow for HCl dissociation independently from nuclear quantum effects. In order to provide the molecular underpinnings of these observations, the classical and quantum free energy profiles were decomposed along the dissociation coordinate in terms of the corresponding internal energy and entropy profiles. What decides in the end about acid dissociation, and thus ion pair formation, in a specific microsolvated water cluster at room temperature is found to be a fierce competition between classical configurational entropy and internal energy, where the former stabilizes the undissociated state whereas the latter favors dissociation. It is expected that these are generic findings with broad implications on acid-base chemistry depending on temperature in small water assemblies.
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Affiliation(s)
| | - Dominik Marx
- Lehrstuhl für Theoretische ChemieRuhr-Universität Bochum44780BochumGermany
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12
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Cota R, van Dam EP, Woutersen S, Bakker HJ. Slowing Down of the Molecular Reorientation of Water in Concentrated Alkaline Solutions. J Phys Chem B 2020; 124:8309-8316. [PMID: 32841025 PMCID: PMC7520889 DOI: 10.1021/acs.jpcb.0c03614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is generally accepted that the hydroxide ion (OH-) is a strong hydrogen bond acceptor and that its anomalously high diffusion constant in water results from a Grotthuss-like structural diffusion mechanism. However, the spatial extent over which OH- ions influence the dynamics of the hydrogen-bond network of water remained largely unclear. Here, we measure the ultrafast dynamics of OH groups of HDO molecules interacting with the deuterated hydroxide ion OD-. For solutions with OD- concentrations up to 4 M, we find that HDO molecules that are not directly interacting with the ions have a reorientation time constant of ∼2.7 ps, similar to that of pure liquid water. When the concentration of OD- ions is increased, the reorientation time constant increases, indicating a strong slowing down of the structural dynamics of the solution.
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Affiliation(s)
- Roberto Cota
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, Netherlands.,AMOLF, Science Park 104, 1098 XG Amsterdam, Netherlands
| | | | - Sander Woutersen
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, Netherlands
| | - Huib J Bakker
- AMOLF, Science Park 104, 1098 XG Amsterdam, Netherlands
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13
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Brieuc F, Schran C, Uhl F, Forbert H, Marx D. Converged quantum simulations of reactive solutes in superfluid helium: The Bochum perspective. J Chem Phys 2020; 152:210901. [DOI: 10.1063/5.0008309] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- Fabien Brieuc
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Christoph Schran
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Felix Uhl
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Harald Forbert
- Center for Solvation Science ZEMOS, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
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14
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Feil S. Ultrakalte Säure‐Base‐Chemie. CHEM UNSERER ZEIT 2020. [DOI: 10.1002/ciuz.202080074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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15
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Thaler B, Heim P, Treiber L, Koch M. Ultrafast photoinduced dynamics of single atoms solvated inside helium nanodroplets. J Chem Phys 2020; 152:014307. [PMID: 31914752 DOI: 10.1063/1.5130145] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Helium nanodroplets can serve as reaction containers for photoinduced time-resolved studies of cold, isolated molecular systems that are otherwise inaccessible. Recently, three different dynamical processes, triggered by photoexcitation of a single atom inside a droplet, were observed in their natural time scale: Expansion of the He solvation shell (He bubble) within 600 fs initiates a collective bubble oscillation with a ∼30 ps oscillation period, followed by dopant ejection after ∼60 ps. Here, we present a systematic investigation of these processes by combining time-resolved photoelectron and photoion spectroscopy with time-dependent He density functional theory simulations. By variation of the photoexcitation energy, we find that the full excess excitation energy, represented by the blue-shifted in-droplet excitation band, is completely transferred to the He environment during the bubble expansion. Surprisingly, we find that variation of the droplet size has only a minor influence on the ejection time, providing insight into the spatial distribution of the ground-state atoms before photoexcitation. Simulated particle trajectories after photoexcitation are in agreement with experimental observations and suggest that the majority of ground-state atoms are located at around 16 Å below the droplet surface. Bubble expansion and oscillation are purely local effects, depending only on the ultimate dopant environment. These solvation-induced dynamics will be superimposed on intramolecular dynamics of molecular systems, and a mechanistic description is fundamental for the interpretation of future experiments.
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Affiliation(s)
- Bernhard Thaler
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria
| | - Pascal Heim
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria
| | - Leonhard Treiber
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria
| | - Markus Koch
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria
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16
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Roy TK, Mani D, Schwaab G, Havenith M. A close competition between O–H⋯O and O–H⋯π hydrogen bonding: IR spectroscopy of anisole–methanol complex in helium nanodroplets. Phys Chem Chem Phys 2020; 22:22408-22416. [DOI: 10.1039/d0cp02589e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Anisole forms O–H⋯O as well O–H⋯π bound complexes with methanol.
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Affiliation(s)
- Tarun Kumar Roy
- Lehrstuhl für Physikalische Chemie II
- Ruhr-Universität Bochum
- Bochum
- Germany
| | - Devendra Mani
- Lehrstuhl für Physikalische Chemie II
- Ruhr-Universität Bochum
- Bochum
- Germany
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II
- Ruhr-Universität Bochum
- Bochum
- Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II
- Ruhr-Universität Bochum
- Bochum
- Germany
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17
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Bresnahan CG, David R, Milet A, Kumar R. Ion Pairing in HCl-Water Clusters: From Electronic Structure Investigations to Multiconfigurational Force-Field Development. J Phys Chem A 2019; 123:9371-9381. [PMID: 31589444 DOI: 10.1021/acs.jpca.9b07775] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In the bulk, condensed-phase HCl exists as a dissociated Cl- ion and a proton that is delocalized over solvating water molecules. However, in the gas phase, HCl is covalent, and even on the introduction of hydrating water molecules, the HCl covalent state dominates small clusters and is relevant at larger clusters including 21 water molecules. Electronic structure calculations (at the MP2 level) and ab initio metadynamics simulations (at the DFT level) have been carried out on HCl-(H2O)n clusters with n = 2-22 to investigate distinct solvation environments in clusters from covalent HCl structure, to contact ion pairs and solvent-separated ion pairs. The data were further used to train and validate a multiconfigurational force-field for HCl-water clusters that incorporates covalent HCl states into the MS-EVB3.2 formalism. Additionally, the many-body interaction of the Cl- ion with water and the excess proton was modeled by the introduction of two geometric three-body terms that incorporates the dominant many-body interaction in an efficient noniterative manner.
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Affiliation(s)
- Caitlin G Bresnahan
- Department of Chemistry , 232 Choppin Hall , Louisiana State University , Baton Rouge , Louisiana 70803 , United States
| | - Rolf David
- Department of Chemistry , 232 Choppin Hall , Louisiana State University , Baton Rouge , Louisiana 70803 , United States.,Univ. Grenoble Alpes, CNRS, DCM , 38000 Grenoble , France
| | - Anne Milet
- Univ. Grenoble Alpes, CNRS, DCM , 38000 Grenoble , France
| | - Revati Kumar
- Department of Chemistry , 232 Choppin Hall , Louisiana State University , Baton Rouge , Louisiana 70803 , United States
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18
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Schran C, Marx D. Quantum nature of the hydrogen bond from ambient conditions down to ultra-low temperatures. Phys Chem Chem Phys 2019; 21:24967-24975. [DOI: 10.1039/c9cp04795f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Quantum simulations reveal strong temperature effects for weak hydrogen bonds and differences in quantum delocalization between various hydrogen-bonded systems.
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Affiliation(s)
- Christoph Schran
- Lehrstuhl für Theoretische Chemie
- Ruhr-Universität Bochum
- 44780 Bochum
- Germany
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie
- Ruhr-Universität Bochum
- 44780 Bochum
- Germany
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