1
|
Agieienko V, Buchner R. What is behind a gas stream scrubbing liquid? Monoethanolamine/water mixtures as seen by dielectric relaxation spectroscopy. Phys Chem Chem Phys 2024; 26:2312-2323. [PMID: 38165687 DOI: 10.1039/d3cp05027k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
High-quality dielectric data for monoethanolamine (MEA)/water mixtures covering the entire miscibility range are presented. For MEA concentrations c1 ≥ 1 M the obtained complex permittivity spectra, covering the frequency range from 0.05 to 89 GHz, are best described by a sum of four Debye relaxations. Modes at ∼3 GHz and ∼10 GHz are solute-specific. Whilst the first can be assigned to MEA aggregates, the second is a composite arising from "free" MEA dipoles with dynamically retarded water hydrating them. The relaxations at ∼18 GHz and ∼200 GHz essentially reflect the cooperative H-bond fluctuations of more-or-less unperturbed "bulk" water, albeit with minor solute contributions. Evaluation of the bulk-water amplitude reveals that in water-rich mixtures (c1 ≤ 3.5 M) Zt = 3.5 ± 0.2 H2O molecules hydrate a MEA molecule. Then Zt drops linearly, reaching zero for neat MEA. Supported by the literature, this concentration dependence suggests that only H2O molecules H-bonded to the NH2 and OH groups of MEA contribute to Zt. At concentrations beyond hydration shell overlap (c1 ≥ 3.5 M) these H-bonds are gradually eliminated, while new interactions with neighboring MEA molecules are formed. From the evaluation of the MEA-specific amplitudes we conclude that for c1 ≥ 2 M, including neat MEA, ∼35% of the solute molecules are in aggregates, where breaking the intermolecular NH⋯O hydrogen bond determines the dynamics.
Collapse
Affiliation(s)
- Vira Agieienko
- Laboratory of Engineering Chemistry, Research Institute for Chemistry, Lobachevsky State University of Nizhny Novgorod, 23 Gagarina av., 603022 Nizhny Novgorod, Russian Federation.
- Nanotechnology and Biotechnology Department, Nizhny Novgorod State Technical University n.a. R.E. Alekseev, 24 Minina str., 603950 Nizhny Novgorod, Russian Federation
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| |
Collapse
|
2
|
Srinivasa MK, Lee J, Hyun K, Yoo HD. Modifying Kohlrausch's Law to Describe Nonaqueous Electrolytes for Lithium-Ion Batteries. ACS APPLIED MATERIALS & INTERFACES 2023; 15:59296-59308. [PMID: 38088367 DOI: 10.1021/acsami.3c09396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
To develop next-generation lithium-ion batteries with enhanced stability and safety, it is crucial to understand the physicochemical principles of nonaqueous electrolytes. Kohlrausch's law describes a linear decrease in the molar conductivity (Λ) with respect to the square root of the molarity of strong electrolytes at lower concentrations. This empirical law explains the impeded ionic mobility at higher concentrations due to ionic interactions, i.e., relaxation and asymmetric effects. However, this law does not hold at higher concentrations due to the ionic association that alleviates the ionic interactions and retards the decrease in the Λ. Especially, the anomalously stagnant decrease in the Λ near the solubility limit has not been clearly explained, calling for the consideration of other concentration-dependent factors such as the mean activity coefficient (γ±), viscosity (η), and dielectric constant (ε). Herein, we develop a systematic method to modify Kohlrausch's law. First, we install the ionic association constant, and the theoretical estimation is compared with the experimental results to induce the correction function that is related with the previously neglected concentration-dependent factors. Thus, the induced correction function was close to the rectified linear unit (ReLU) function, which has been widely used in the field of artificial intelligence. The modified Kohlrausch's law with the ReLU-type correction function provides a highly precise and reliable data fitting, and the fitted parameters showed clear concentration dependency and straightforward interpretability. As a result, this method effectively generalized Kohlrausch's law for nonaqueous electrolytes at higher concentrations up to the solubility limit of 3.0-3.5 M. Moreover, the modified Kohlrausch's law inspired us to discover the physical origins of the anomalously stagnant Λ profiles near the solubility limit; and the most relevant physical origin of the anomaly was the concentration dependency of the γ± and η, which grow exponentially above a critical concentration.
Collapse
Affiliation(s)
- Madhusudana Koratikere Srinivasa
- Department of Chemistry and Chemical Institute for Functional Materials, Pusan National University, Busan 46241, Republic of Korea
| | - Jeonghyeon Lee
- School of Chemical and Biomolecular Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Kyu Hyun
- School of Chemical and Biomolecular Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Hyun Deog Yoo
- Department of Chemistry and Chemical Institute for Functional Materials, Pusan National University, Busan 46241, Republic of Korea
| |
Collapse
|
3
|
Penkov NV. Terahertz spectroscopy as a method for investigation of hydration shells of biomolecules. Biophys Rev 2023; 15:833-849. [PMID: 37974994 PMCID: PMC10643733 DOI: 10.1007/s12551-023-01131-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 08/30/2023] [Indexed: 11/19/2023] Open
Abstract
The hydration of biomolecules is one of the fundamental processes underlying the construction of living matter. The formation of the native conformation of most biomolecules is possible only in an aqueous environment. At the same time, not only water affects the structure of biomolecules, but also biomolecules affect the structure of water, forming hydration shells. However, the study of the structure of biomolecules is given much more attention than their hydration shells. A real breakthrough in the study of hydration occurred with the development of the THz spectroscopy method, which showed that the hydration shell of biomolecules is not limited to 1-2 layers of strongly bound water, but also includes more distant areas of hydration with altered molecular dynamics. This review examines the fundamental features of the THz frequency range as a source of information about the structural and dynamic characteristics of water that change during hydration. The applied approaches to the study of hydration shells of biomolecules based on THz spectroscopy are described. The data on the hydration of biomolecules of all main types obtained from the beginning of the application of THz spectroscopy to the present are summarized. The emphasis is placed on the possible participation of extended hydration shells in the realization of the biological functions of biomolecules and at the same time on the insufficient knowledge of their structural and dynamic characteristics.
Collapse
Affiliation(s)
- Nikita V. Penkov
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics RAS, 142290 Pushchino, Russia
| |
Collapse
|
4
|
Reynolds JG. Zavitsas’ model of aqueous NaF solution activities utilizing hydration numbers reported from Dielectric Relaxation spectroscopy. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
|
5
|
Hydration of the Neurotransmitter γ-Aminobutyric Acid and its Isomer α-Aminobutyric Acid. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
6
|
Krevert CS, Gunkel L, Haese C, Hunger J. Ion-specific binding of cations to the carboxylate and of anions to the amide of alanylalanine. Commun Chem 2022; 5:173. [PMID: 36697920 PMCID: PMC9814750 DOI: 10.1038/s42004-022-00789-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Studies of ion-specific effects on oligopeptides have aided our understanding of Hofmeister effects on proteins, yet the use of different model peptides and different experimental sensitivities have led to conflicting conclusions. To resolve these controversies, we study a small model peptide, L-Alanyl-L-alanine (2Ala), carrying all fundamental chemical protein motifs: C-terminus, amide bond, and N-terminus. We elucidate the effect of GdmCl, LiCl, KCl, KI, and KSCN by combining dielectric relaxation, nuclear magnetic resonance (1H-NMR), and (two-dimensional) infrared spectroscopy. Our dielectric results show that all ions reduce the rotational mobility of 2Ala, yet the magnitude of the reduction is larger for denaturing cations than for anions. The NMR chemical shifts of the amide group are particularly sensitive to denaturing anions, indicative of anion-amide interactions. Infrared experiments reveal that LiCl alters the spectral homogeneity and dynamics of the carboxylate, but not the amide group. Interaction of LiCl with the negatively charged pole of 2Ala, the COO- group, can explain the marked cationic effect on dipolar rotation, while interaction of anions between the poles, at the amide, only weakly perturbs dipolar dynamics. As such, our results provide a unifying view on ions' preferential interaction sites at 2Ala and help rationalize Hofmeister effects on proteins.
Collapse
Affiliation(s)
- Carola Sophie Krevert
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Lucas Gunkel
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Constantin Haese
- grid.419547.a0000 0001 1010 1663Department of Molecular Electronics, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Johannes Hunger
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| |
Collapse
|
7
|
Volkov AA, Chuchupal SV. Dielectric spectra of liquid water: Ultrabroadband modeling and interpretation. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
8
|
Moreno-Gómez N, Vargas EF, Buchner R. Ionic effects on supramolecular hosts: solvation and counter-ion binding in polar media. Phys Chem Chem Phys 2022; 24:2040-2050. [PMID: 35006219 DOI: 10.1039/d1cp05444a] [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
For the progress of synthetic supramolecular chemistry in aqueous solution the design of host molecules soluble in this medium is essential. A possible route is the introduction of ionic residues, with the additional advantage that also electrostatic interactions can be used to form supramolecular architectures. In this work we study the effect of different ionic substituents on a resorcin[4]arene host on solvation and counterion binding in water and dimethyl sulfoxide (DMSO). To do so, we combine dielectric relaxation spectroscopy (DRS) at 298.15 K and dilute-solution conductivity measurements covering 278.15-308.15 K. The results indicate that studied substituents lead to a comparable increase in solubility in both water and the dipolar-aprotic DMSO. However, solvation and counterion binding not only depend on the nature of the ionic substituent but also on the solvent. Although intrinsically hydrophobic in nature, resorcin[4]arenes with ionic substituents also show strong hydrophilic hydration in water, with the extent depending on the nature of the ionic group. In contrast to that, solvophobicity apparently dominates the interactions of DMSO with the solute. Counterion binding was found for both solvents and is essentially determined by solvent polarity. It appears that, compared to neat DMSO, the solubility of the cationic resorcin[4]arene with dimethylamine substituents is strongly increased in water-DMSO mixtures due to the formation of hydrogen bonds between two DMSO molecules and one water molecule.
Collapse
Affiliation(s)
- Nicolás Moreno-Gómez
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany. .,Laboratorio de Termodinámica de Soluciones, Departamento de Química, Universidad de Los Andes, Cr. 1 No. 18 A-12, Bogotá, Colombia.
| | - Edgar F Vargas
- Laboratorio de Termodinámica de Soluciones, Departamento de Química, Universidad de Los Andes, Cr. 1 No. 18 A-12, Bogotá, Colombia.
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany.
| |
Collapse
|
9
|
Ghosh D, Sakpal SS, Chatterjee S, Deshmukh SH, Kwon H, Kim YS, Bagchi S. Association-Dissociation Dynamics of Ionic Electrolytes in Low Dielectric Medium. J Phys Chem B 2021; 126:239-248. [PMID: 34961310 DOI: 10.1021/acs.jpcb.1c08613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ionic electrolytes are known to form various complexes which exist in dynamic equilibrium in a low dielectric medium. However, structural characterization of these complexes has always posed a great challenge to the scientific community. An additional challenge is the estimation of the dynamic association-dissociation time scales (lifetime of the complexes), which are key to the fundamental understanding of ion transport. In this work, we have used a combination of infrared absorption spectroscopy, two-dimensional infrared spectroscopy, molecular dynamics simulations, and density functional theory calculations to characterize the various ion complexes formed by the thiocyanate-based ionic electrolytes as a function of different cations in a low dielectric medium. Our results demonstrate that thiocyanate is an excellent vibrational reporter of the heterogeneous ion complexes undergoing association-dissociation dynamics. We find that the ionic electrolytes exist as contact ion pairs, dimers, and clusters in a low dielectric medium. The relative ratios of the various ion complexes are sensitive to the cations. In addition to the interactions between the thiocyanate anion and the countercation, the solute-solvent interactions drive the dynamic equilibrium. We have estimated the association-dissociation dynamics time scales from two-dimensional infrared spectroscopy. The exchange time scale involving the cluster is faster than that between a dimer and an ion pair. Moreover, we find that the dynamic equilibrium between the cluster and another ion complex is correlated to the solvent fluctuations.
Collapse
Affiliation(s)
- Deborin Ghosh
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Sushil S Sakpal
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Srijan Chatterjee
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Samadhan H Deshmukh
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Hyejin Kwon
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Korea
| | - Yung Sam Kim
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Korea
| | - Sayan Bagchi
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
10
|
Rohman N, Mohiuddin T. Dielectric Relaxation of Decyltrimethylammonium Bromide-Water-Styrene Oil-in-Water Microemulsion. J SOLUTION CHEM 2021. [DOI: 10.1007/s10953-021-01108-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
11
|
Friesen S, Fedotova MV, Kruchinin SE, Buchner R. Hydration and dynamics of L-glutamate ion in aqueous solution. Phys Chem Chem Phys 2021; 23:1590-1600. [PMID: 33409510 DOI: 10.1039/d0cp05489e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Aqueous solutions of sodium l-glutamate (NaGlu) in the concentration range 0 < c/M ≤ 1.90 at 25 °C were investigated by dielectric relaxation spectroscopy (DRS) and statistical mechanics (1D-RISM and 3D-RISM calculations) to study the hydration and dynamics of the l-glutamate (Glu-) anion. Although at c → 0 water molecules beyond the first hydration shell are dynamically affected, Glu- hydration is rather fragile and for c ⪆ 0.3 M apparently restricted to H2O molecules hydrogen bonding to the carboxylate groups. These hydrating dipoles are roughly parallel to the anion moment, leading to a significantly enhanced effective dipole moment of Glu-. However, l-glutamate dynamics is determined by the rotational diffusion of individual anions under hydrodynamic slip boundary conditions. Thus, the lifetime of the hydrate complexes, as well as of possibly formed [Na+Glu-]0 ionpairs and l-glutamate aggregates, cannot exceed the characteristic timescale for Glu- rotation.
Collapse
Affiliation(s)
- Sergej Friesen
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany.
| | - Marina V Fedotova
- G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Akademicheskaya St. 1, 153045 Ivanovo, Russian Federation.
| | - Sergey E Kruchinin
- G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Akademicheskaya St. 1, 153045 Ivanovo, Russian Federation.
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany.
| |
Collapse
|
12
|
Watanabe H, Arai N, Kameda Y, Buchner R, Umebayashi Y. Effect of Brønsted Acidity on Ion Conduction in Fluorinated Acetic Acid and N-Methylimidazole Equimolar Mixtures as Pseudo-protic Ionic Liquids. J Phys Chem B 2020; 124:11157-11164. [PMID: 33198463 DOI: 10.1021/acs.jpcb.0c07706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To clarify proton conduction mechanism in protic ionic liquids (PILs) and pseudo-PILs (pPILs), equimolar mixtures of N-methylimidazole (C1Im) with fluorinated acetic acids were investigated by Raman spectroscopy, X-ray scattering, and dielectric relaxation spectroscopy (DRS). Only the ionic species exist in the equimolar mixture of C1Im and HTFA (HTFA: trifluoroacetic acid). On the other hand, the equimolar mixture of C1Im and HDFA (HDFA: difluoroacetic acid) consists of both ionic and electrically neutral species. In particular, not only the electrostatic but also van der Waals interactions with the F atoms were observed in the liquid structures of both [C1hIm+][TFA-] and [C1hIm+][DFA-]. The concept for proton conduction mechanism that we have proposed in previous study was revisited; the proton conduction mechanism could be classified with two linear free energy relationship lines for proton exchange reaction and translation/rotation of proton carriers. Our results exhibit that the proton conduction mechanism changes from proton hopping to vehicle mechanism with increasing acidity of an acid HA in PILs.
Collapse
Affiliation(s)
- Hikari Watanabe
- Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, Chiba 278-8510, Japan
| | - Nana Arai
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan
| | - Yasuo Kameda
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata 990-8560, Japan
| | - Richard Buchner
- Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstr. 31, Regensburg 93053, Germany
| | - Yasuhiro Umebayashi
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan
| |
Collapse
|
13
|
Medoš Ž, Friesen S, Buchner R, Bešter-Rogač M. Interplay between aggregation number, micelle charge and hydration of catanionic surfactants. Phys Chem Chem Phys 2020; 22:9998-10009. [PMID: 32365150 DOI: 10.1039/d0cp00877j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Catanionic mixtures are commonly used in applications due to synergetic properties of both cationic and anionic surfactants. To better understand the mechanism of the micellization process of salt-free catanionic surfactants, alkyltrimethylammonium alkanecarboxylates, [CxMe3N]+[Cy]-, with medium to long alkyl chains on both cation and anion (x,y = 6-10), were investigated in aqueous solution by density and zeta potential measurements, isothermal titration calorimetry (ITC), and dielectric relaxation spectroscopy (DRS). The obtained ITC data was analysed with the help of a two-step model equation, yielding the thermodynamic parameters, micelle charge and aggregation numbers. Comparison with the "parent" decyltrimethylammonium chloride and sodium decanoate reveals that combined dehydration of both alkyl chains increases entropy upon micellization. In the first step neutral smaller micelles with partly dehydrated alkyl chains are formed, while in the second step larger charged micelles with fully dehydrated alkyl chains are equally favourable. At low temperature both formations are thermodynamically equivalent, while with increasing temperature neutral micelles become more entropically favourable and charged micelles more enthalpically favourable. The resulting average micelle charge and average aggregation number are decreasing with temperature. From the DRS spectra, effective hydration numbers of the free monomers and micelles were deduced and are comparable to the "parent" cationic surfactant micelles.
Collapse
Affiliation(s)
- Žiga Medoš
- Faculty of Chemistry and Chemical Technology, Večna pot 113, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
| | - Sergej Friesen
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93053 Regensburg, Germany.
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93053 Regensburg, Germany.
| | - Marija Bešter-Rogač
- Faculty of Chemistry and Chemical Technology, Večna pot 113, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
| |
Collapse
|
14
|
Microscopic insights into the phase transition of poly(N-isopropylacrylamide) in aqueous media: Effects of molecular weight and polymer concentration. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.112025] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
15
|
Buchner R, Wachter W, Hefter G. Systematic Variations of Ion Hydration in Aqueous Alkali Metal Fluoride Solutions. J Phys Chem B 2019; 123:10868-10876. [DOI: 10.1021/acs.jpcb.9b09694] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany
| | - Wolfgang Wachter
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany
| | - Glenn Hefter
- Chemistry Department, Murdoch University, Murdoch, WA 6150, Australia
| |
Collapse
|
16
|
Hofmann MJ, Leontidis E, Motschmann H. The influence of lanthanide-(III)-nitrates on adsorbed monolayers of dodecylphosphorylcholine at the air-water interface. J Colloid Interface Sci 2019; 548:217-223. [DOI: 10.1016/j.jcis.2019.03.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/18/2019] [Accepted: 03/20/2019] [Indexed: 10/27/2022]
|
17
|
Watanabe H, Umecky T, Arai N, Nazet A, Takamuku T, Harris KR, Kameda Y, Buchner R, Umebayashi Y. Possible Proton Conduction Mechanism in Pseudo-Protic Ionic Liquids: A Concept of Specific Proton Conduction. J Phys Chem B 2019; 123:6244-6252. [DOI: 10.1021/acs.jpcb.9b03185] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Hikari Watanabe
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi, 2-no-cho, Nishi-ku, Niigata City 950-2181, Japan
| | - Tatsuya Umecky
- Graduate School of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502, Japan
| | - Nana Arai
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi, 2-no-cho, Nishi-ku, Niigata City 950-2181, Japan
| | - Andreas Nazet
- Institute of Theoretical and Physical Chemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
| | - Toshiyuki Takamuku
- Graduate School of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502, Japan
| | - Kenneth R. Harris
- School of Science, The University of New South Wales, P.O. Box 7916, Canberra BC, Australian Capital Territory 2610, Australia
| | - Yasuo Kameda
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, 1-4-12, Kojirakawa-machi, Yamagata City, Yamagata 990-8560, Japan
| | - Richard Buchner
- Institute of Theoretical and Physical Chemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
| | - Yasuhiro Umebayashi
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi, 2-no-cho, Nishi-ku, Niigata City 950-2181, Japan
| |
Collapse
|
18
|
Tarif E, Saha B, Mukherjee K, De P, Biswas R. Exploring Aqueous Solution Dynamics of an Amphiphilic Diblock Copolymer: Dielectric Relaxation and Time-Resolved Fluorescence Measurements. J Phys Chem B 2019; 123:5892-5901. [DOI: 10.1021/acs.jpcb.9b00889] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ejaj Tarif
- Chemical, Biological and Macromolecular Sciences (CBMS), S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700106, India
| | - Biswajit Saha
- Polymer Research Centre and Centre for Advanced Functional Materials, Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, West Bengal, India
| | - Kallol Mukherjee
- Chemical, Biological and Macromolecular Sciences (CBMS), S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700106, India
| | - Priyadarsi De
- Polymer Research Centre and Centre for Advanced Functional Materials, Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia 741246, West Bengal, India
| | - Ranjit Biswas
- Chemical, Biological and Macromolecular Sciences (CBMS), S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700106, India
| |
Collapse
|
19
|
Moreno-Gómez N, Vargas EF, Buchner R. Hydration and Counterion Binding of an Aminomethylated Resorcin[4]arene. J Phys Chem B 2019; 123:1840-1846. [DOI: 10.1021/acs.jpcb.8b11900] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nicolás Moreno-Gómez
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
- Laboratorio de Termodinámica de Soluciones, Departamento de Química, Universidad de Los Andes, Cr. 1 No. 18 A-12, Bogotá, Colombia
| | - Edgar F. Vargas
- Laboratorio de Termodinámica de Soluciones, Departamento de Química, Universidad de Los Andes, Cr. 1 No. 18 A-12, Bogotá, Colombia
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| |
Collapse
|
20
|
Friesen S, Hefter G, Buchner R. Cation Hydration and Ion Pairing in Aqueous Solutions of MgCl2 and CaCl2. J Phys Chem B 2019; 123:891-900. [DOI: 10.1021/acs.jpcb.8b11131] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Sergej Friesen
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Regensburg 93040, Germany
| | - Glenn Hefter
- Chemistry Department, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Regensburg 93040, Germany
| |
Collapse
|
21
|
Shaukat S, Fedotova MV, Kruchinin SE, Bešter-Rogač M, Podlipnik Č, Buchner R. Hydration and ion association of aqueous choline chloride and chlorocholine chloride. Phys Chem Chem Phys 2019; 21:10970-10980. [DOI: 10.1039/c9cp01016e] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Choline hydration occurs predominantly via its hydroxyl group, and weak contact ion pair formation with Cl− is via the onium moiety.
Collapse
Affiliation(s)
- Saadia Shaukat
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| | - Marina V. Fedotova
- G.A. Krestov Institute of Solution Chemistry
- Russian Academy of Sciences
- 153045 Ivanovo
- Russian Federation
| | - Sergey E. Kruchinin
- G.A. Krestov Institute of Solution Chemistry
- Russian Academy of Sciences
- 153045 Ivanovo
- Russian Federation
| | - Marija Bešter-Rogač
- Faculty of Chemistry and Chemical Technology
- Večna pot 113
- University of Ljubljana
- SI-1000 Ljubljana
- Slovenia
| | - Črtomir Podlipnik
- Faculty of Chemistry and Chemical Technology
- Večna pot 113
- University of Ljubljana
- SI-1000 Ljubljana
- Slovenia
| | - Richard Buchner
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| |
Collapse
|
22
|
Płowaś-Korus I, Buchner R. Structure, molecular dynamics, and interactions in aqueous xylitol solutions. Phys Chem Chem Phys 2019; 21:24061-24069. [DOI: 10.1039/c9cp04547c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Broad-band dielectric relaxation studies of xylitol-water mixture show distinctly different dynamics for distal and central –OH of xylitol molecules and indicates the presence of loose xylitol aggregates.
Collapse
Affiliation(s)
- Iwona Płowaś-Korus
- Institute of Molecular Physics
- Polish Academy of Sciences
- 60-179 Poznań
- Poland
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie
- Universität Regensburg
- 93040 Regensburg
- Germany
| |
Collapse
|
23
|
Nazet A, Buchner R. Dielectric response and transport properties of alkylammonium formate ionic liquids. J Chem Phys 2018; 148:193836. [DOI: 10.1063/1.5013097] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Andreas Nazet
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany
| |
Collapse
|
24
|
Agieienko V, Hölzl C, Horinek D, Buchner R. The Interplay of Methyl-Group Distribution and Hydration Pattern of Isomeric Amphiphilic Osmolytes. J Phys Chem B 2018; 122:5972-5983. [DOI: 10.1021/acs.jpcb.8b01699] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Vira Agieienko
- A. M. Butlerov Institute of Chemistry, Kazan Federal University, 420008 Kazan, Russia
| | - Christoph Hölzl
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| | - Dominik Horinek
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| |
Collapse
|
25
|
Friesen S, Krickl S, Luger M, Nazet A, Hefter G, Buchner R. Hydration and ion association of La3+ and Eu3+ salts in aqueous solution. Phys Chem Chem Phys 2018. [DOI: 10.1039/c8cp00248g] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Lanthanide ions affect water out to the third shell and form double solvent-separated and solvent-shared ion pairs.
Collapse
Affiliation(s)
- Sergej Friesen
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| | - Sebastian Krickl
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| | - Magdalena Luger
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| | - Andreas Nazet
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| | - Glenn Hefter
- Chemistry Department
- Murdoch University
- Murdoch
- Australia
| | - Richard Buchner
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| |
Collapse
|
26
|
Ren G, Chen L, Wang Y. Dynamic heterogeneity in aqueous ionic solutions. Phys Chem Chem Phys 2018; 20:21313-21324. [DOI: 10.1039/c8cp02787k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is well known that supercooled liquids have heterogeneous dynamics, but it is still unclear whether dynamic heterogeneity also exists in aqueous ionic solutions at room or even higher temperatures.
Collapse
Affiliation(s)
- Gan Ren
- Department of Physics
- Civil Aviation Flight University of China
- Guanghan
- China
| | - Lin Chen
- State Key Laboratory of Environment-Friendly Energy Material
- Southwest University of Science and Technology
- Mianyang
- China
| | - Yanting Wang
- CAS Key Laboratory of Theoretical Physics
- Institute of Theoretical Physics
- Chinese Academy of Sciences
- Beijing
- China
| |
Collapse
|
27
|
Moreno-Gómez N, Vargas EF, Buchner R. The effect of alkyl-chain branching on the hydration and ion association of tetrabutylammonium cations. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.09.123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
28
|
Yang G, Neretnieks I, Holmboe M. Atomistic simulations of cation hydration in sodium and calcium montmorillonite nanopores. J Chem Phys 2017; 147:084705. [PMID: 28863548 DOI: 10.1063/1.4992001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
During the last four decades, numerous studies have been directed to the swelling smectite-rich clays in the context of high-level radioactive waste applications and waste-liners for contaminated sites. The swelling properties of clay mineral particles arise due to hydration of the interlayer cations and the diffuse double layers formed near the negatively charged montmorillonite (MMT) surfaces. To accurately study the cation hydration in the interlayer nanopores of MMT, solvent-solute and solvent-clay surface interactions (i.e., the solvation effects and the shape effects) on the atomic level should be taken into account, in contrast to many recent electric double layer based methodologies using continuum models. Therefore, in this research we employed fully atomistic simulations using classical molecular dynamics (MD) simulations, the software package GROMACS along with the CLAYFF forcefield and the SPC/E water model. We present the ion distributions and the deformation of the hydrated coordination structures, i.e., the hydration shells of Na+ and Ca2+ in the interlayer, respectively, for MMT in the first-layer, the second-layer, the third-layer, the fourth-layer, and the fifth-layer (1W, 2W, 3W, 4W, and 5W) hydrate states. Our MD simulations show that Na+ in Na-MMT nanopores have an affinity to the ditrigonal cavities of the clay layers and form transient inner-sphere complexes at about 3.8 Å from clay midplane at water contents less than the 5W hydration state. However, these phenomena are not observed in Ca-MMT regardless of swelling states. For Na-MMT, each Na+ is coordinated to four water molecules and one oxygen atom of the clay basal-plane in the first hydration shell at the 1W hydration state, and with five to six water molecules in the first hydration shell within a radius of 3.1 Å at all higher water contents. In Ca-MMT, however each Ca2+ is coordinated to approximately seven water molecules in the first hydration shell at the 1W hydration state and about eight water molecules in the first hydration shell within a radius of 3.3 Å at all higher hydration states. Moreover, the MD results show that the complete hydration shells are nearly spherical with an orthogonal coordination sphere. They could only be formed when the basal spacing d001 ≥ 18.7 Å, i.e., approximately, the interlayer separation h ≥ 10 Å. Comparison between DFT and MD simulations shows that DFT failed to reproduce the outer-sphere complexes in the Stern-layer (within ∼5.0 Å from the clay basal-plane), observed in the MD simulations.
Collapse
Affiliation(s)
- Guomin Yang
- Department of Chemical Engineering, Royal Institute of Technology, S-100 44 Stockholm, Sweden
| | - Ivars Neretnieks
- Department of Chemical Engineering, Royal Institute of Technology, S-100 44 Stockholm, Sweden
| | | |
Collapse
|
29
|
Nazet A, Weiß L, Buchner R. Dielectric relaxation of nitromethane and its mixtures with ethylammonium nitrate: Evidence for strong ion association induced by hydrogen bonding. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2016.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
30
|
Kwon Y, Lee J, Park S. Effect of ion–ligand binding on ion pairing dynamics studied by two-dimensional infrared spectroscopy. Phys Chem Chem Phys 2017; 19:10889-10897. [DOI: 10.1039/c6cp08852j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cation-specific ion pairing dynamics between M+ (M = Ag or Cu) and SCN− in N,N-dimethylthioformamide (DMTF) are studied by probing the nitrile (CN) stretching vibration.
Collapse
Affiliation(s)
- YoungAh Kwon
- Department of Chemistry
- Korea University
- Seoul
- Korea
| | - Junho Lee
- Department of Chemistry
- Korea University
- Seoul
- Korea
| | - Sungnam Park
- Department of Chemistry
- Korea University
- Seoul
- Korea
| |
Collapse
|
31
|
Agieienko V, Horinek D, Buchner R. Hydration and self-aggregation of a neutral cosolute from dielectric relaxation spectroscopy and MD simulations: the case of 1,3-dimethylurea. Phys Chem Chem Phys 2017; 19:219-230. [DOI: 10.1039/c6cp07407c] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1,3-Dimethylurea irrotationally binds 1–2H2O molecules close to its carbonyl and impedes dynamics of ca. 40 H2O molecules by methyl substituents.
Collapse
Affiliation(s)
- Vira Agieienko
- Department of Physical Chemistry
- Kazan Federal University
- 420008 Kazan
- Russia
- Department of Inorganic Chemistry
| | - Dominik Horinek
- Institut für Physikalische und Theoretische Chemie
- Universität Regensburg
- D-93040 Regensburg
- Germany
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie
- Universität Regensburg
- D-93040 Regensburg
- Germany
| |
Collapse
|
32
|
Dmitrieva OA, Fedotova MV, Buchner R. Evidence for cooperative Na+ and Cl− binding by strongly hydrated l-proline. Phys Chem Chem Phys 2017; 19:20474-20483. [DOI: 10.1039/c7cp04335j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Strongly hydrated l-proline cooperatively binds Na+ and Cl− ions in aqueous solution.
Collapse
Affiliation(s)
- Olga A. Dmitrieva
- G.A. Krestov Institute of Solution Chemistry
- Russian Academy of Sciences
- 153045 Ivanovo
- Russian Federation
| | - Marina V. Fedotova
- G.A. Krestov Institute of Solution Chemistry
- Russian Academy of Sciences
- 153045 Ivanovo
- Russian Federation
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie
- Universität Regensburg
- 93040 Regensburg
- Germany
| |
Collapse
|
33
|
Agieienko V, Buchner R. Urea hydration from dielectric relaxation spectroscopy: old findings confirmed, new insights gained. Phys Chem Chem Phys 2016; 18:2597-607. [PMID: 26700870 DOI: 10.1039/c5cp07604h] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We report results on urea hydration obtained by dielectric relaxation spectroscopy (DRS) in a broad range of concentrations and temperatures. In particular, the effective hydration number and dipole moment of urea have been determined. The observed changes with composition and temperature were found to be insignificant and mainly caused by the changing number density of urea. Similarly, solute reorientation scaled simply with viscosity. In contrast, we find that water reorientation undergoes substantial changes in the presence of urea, resulting in two water fractions. The first corresponds to water molecules strongly bound to urea. These solvent molecules follow the reorientational dynamics of the solute. The second fraction exhibits only a minor increase of its relaxation time (in comparison with pure water) which is not linked to solution viscosity. Its activation energy decreases significantly with urea concentration, indicating a marked decrease of the number of H-bonds among the H2O molecules belonging to this fraction. Noncovalent interactions (NCI) analysis, capable to estimate the strength of the interactions within a cluster, shows that bound water molecules are most probably double-hydrogen bonded to urea via the oxygen atom of the carbonyl group and a cis-hydrogen atom. Due to the increased H-bond strength compared to the water dimer and the rigid position in the formed complex the reorientation of these bound H2O molecules is strongly impeded.
Collapse
Affiliation(s)
- Vira Agieienko
- Department of Physical Chemistry, Kazan Federal University, Kremlevskaya str. 18, 420008 Kazan, Russia.
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Deutschland.
| |
Collapse
|
34
|
Stoppa A, Nazet A, Buchner R, Thoman A, Walther M. Dielectric response and collective dynamics of acetonitrile. J Mol Liq 2015. [DOI: 10.1016/j.molliq.2015.03.045] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
35
|
Eiberweiser A, Nazet A, Kruchinin SE, Fedotova MV, Buchner R. Hydration and Ion Binding of the Osmolyte Ectoine. J Phys Chem B 2015; 119:15203-11. [PMID: 26565946 DOI: 10.1021/acs.jpcb.5b09276] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ectoine is a widespread osmolyte enabling halophilic bacteria to withstand high osmotic stress that has many potential applications ranging from cosmetics to its use as a therapeutic agent. In this contribution, combining experiment and theory, the hydration and ion-binding of this zwitterionic compound was studied to gain information on the functioning of ectoine in particular and of osmolytes in general. Dielectric relaxation spectroscopy was used to determine the effective hydration number of ectoine and its effective dipole moment in aqueous solutions with and without added NaCl. The obtained experimental data were compared with structural results from 1D-RISM and 3D-RISM calculations. It was found that ectoine is strongly hydrated, even in the presence of high salt concentrations. Upon addition of NaCl, ions are bound to ectoine but the formed complexes are not very stable. Interestingly, this osmolyte strongly rises the static relative permittivity of its solutions, shielding thus effectively long-range Coulomb interactions among ions in ectoine-containing solutions. We believe that via this effect, which should be common to all zwitterionic osmolytes, ectoine protects against excessive ions within the cell in addition to its strong osmotic activity protecting against ions outside.
Collapse
Affiliation(s)
- Andreas Eiberweiser
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg , D-93040 Regensburg, Germany
| | - Andreas Nazet
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg , D-93040 Regensburg, Germany
| | - Sergey E Kruchinin
- G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences , Akademicheskaya st. 1, Ivanovo, Russia
| | - Marina V Fedotova
- G. A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences , Akademicheskaya st. 1, Ivanovo, Russia
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg , D-93040 Regensburg, Germany
| |
Collapse
|
36
|
Mukherjee K, Das A, Choudhury S, Barman A, Biswas R. Dielectric Relaxations of (Acetamide + Electrolyte) Deep Eutectic Solvents in the Frequency Window, 0.2 ≤ ν/GHz ≤ 50: Anion and Cation Dependence. J Phys Chem B 2015; 119:8063-71. [DOI: 10.1021/acs.jpcb.5b01502] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kallol Mukherjee
- Chemical, Biological
and Macromolecular Sciences (CBMS), and ‡Condensed Matter
Physics and Material Sciences (CMPMS), S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098, India
| | - Anuradha Das
- Chemical, Biological
and Macromolecular Sciences (CBMS), and ‡Condensed Matter
Physics and Material Sciences (CMPMS), S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098, India
| | - Samiran Choudhury
- Chemical, Biological
and Macromolecular Sciences (CBMS), and ‡Condensed Matter
Physics and Material Sciences (CMPMS), S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098, India
| | - Anjan Barman
- Chemical, Biological
and Macromolecular Sciences (CBMS), and ‡Condensed Matter
Physics and Material Sciences (CMPMS), S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098, India
| | - Ranjit Biswas
- Chemical, Biological
and Macromolecular Sciences (CBMS), and ‡Condensed Matter
Physics and Material Sciences (CMPMS), S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098, India
| |
Collapse
|
37
|
Eiberweiser A, Nazet A, Hefter G, Buchner R. Ion hydration and association in aqueous potassium phosphate solutions. J Phys Chem B 2015; 119:5270-81. [PMID: 25826464 DOI: 10.1021/acs.jpcb.5b01417] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ionic hydration and ion association in aqueous solutions of KH2PO4, K2HPO4, and K3PO4 at 25 °C up to high concentrations have been investigated using dielectric relaxation spectroscopy (DRS). The three phosphate anions were found to be extensively hydrated, with total hydration numbers at infinite dilution of ~11 (for H2PO4(-)), ~20 (HPO4(2-)), and ~39 (PO4(3-)). These values are indicative of the existence of a second hydration shell around HPO4(2-) and especially PO4(3-). Two types of hydrating water molecules could be quantified: irrotationally bound (ib, H2O molecules essentially "frozen" on the DRS time scale) and "slow" (loosely bound water molecules with identifiably slower dynamics than bulk water). For H2PO4(-) over the entire concentration range and for HPO4(2-) and PO4(3-) at concentrations c ≲ 1 mol L(-1), only "slow" H2O was detected; however, at higher concentrations of the latter two anions, an increasing fraction of ib water appears, making up ~50% of the total hydration number close to the saturation limit of K2HPO4. Contrary to common belief, all three salts showed significant ion pair formation, with standard association constants of the 1:1 species increasing in the order: KH2PO4(0)(aq) < KHPO4(-)(aq) < KPO4(2-)(aq). The main type of ion pair in solution shifted from solvent-shared ion pairs (SIPs) to double-solvent-separated ion pairs (2SIPs) in the same sequence.
Collapse
Affiliation(s)
- Andreas Eiberweiser
- †Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, D-93040 Regensburg, Germany
| | - Andreas Nazet
- †Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, D-93040 Regensburg, Germany
| | - Glenn Hefter
- ‡Chemistry Department, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
| | - Richard Buchner
- †Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstr. 31, D-93040 Regensburg, Germany
| |
Collapse
|
38
|
Brandes E, Stage C, Motschmann H, Rieder J, Buchner R. Is surface layering of aqueous alkali halides determined by ion pairing in the bulk solution? J Chem Phys 2014; 141:18C509. [DOI: 10.1063/1.4895969] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
39
|
Dielectric relaxation in isobutyl alcohol-NMP and isobutyl alcohol-DMSO mixtures studied by microwave dielectric relaxation spectroscopy. Colloid Polym Sci 2014. [DOI: 10.1007/s00396-014-3406-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
40
|
Sonnleitner T, Turton DA, Hefter G, Ortner A, Waselikowski S, Walther M, Wynne K, Buchner R. Ultra-Broadband Dielectric and Optical Kerr-Effect Study of the Ionic Liquids Ethyl and Propylammonium Nitrate. J Phys Chem B 2014; 119:8826-41. [PMID: 24945675 DOI: 10.1021/jp502935t] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dielectric relaxation (DR) and optical Kerr-effect (OKE) spectra of the archetypal protic ionic liquids ethyl- and propylammonium nitrate (EAN and PAN) have been measured over an unusually large frequency range from 200 MHz to 10 THz at temperatures (mostly) between 5 and 65 °C. Analysis of the low-frequency α-relaxation, associated with the cooperative relaxations of the cations (DR) and anions (OKE) and any clusters present, indicated that ion reorientation in EAN is decoupled from viscosity and occurs via cooperative relaxation involving large-angle jumps rather than rotational diffusion. Detailed consideration of the high-frequency parts of the DR and OKE spectra showed that the observed intensities were a complex combination of overlapping and possibly coupled modes. In addition to previously identified intermolecular H-bond vibrations, there are significant contributions from the librations of the cations and anions. The present assignments were shown to be consistent with the isotopic shifts observed for deuterated EAN.
Collapse
Affiliation(s)
- Thomas Sonnleitner
- †Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitatsstr. 31, D-93040 Regensburg, Germany
| | - David A Turton
- ‡School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Glenn Hefter
- §Chemistry Department, Murdoch University, Murdoch, W.A. 6150, Australia
| | - Alexander Ortner
- ∥Department of Molecular and Optical Physics, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Stefan Waselikowski
- ∥Department of Molecular and Optical Physics, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Markus Walther
- ∥Department of Molecular and Optical Physics, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - Klaas Wynne
- ‡School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Richard Buchner
- †Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitatsstr. 31, D-93040 Regensburg, Germany
| |
Collapse
|
41
|
Arik E, Altan H, Esenturk O. Dielectric properties of ethanol and gasoline mixtures by terahertz spectroscopy and an effective method for determination of ethanol content of gasoline. J Phys Chem A 2014; 118:3081-9. [PMID: 24701997 DOI: 10.1021/jp500760t] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Investigation of frequency dependent permittivity of mixture solutions provides information on the role of intermolecular interactions on relaxation processes of solvent and solute molecules. In this study the dielectric properties of ethanol/gasoline mixtures in the terahertz spectral region are investigated. Frequency dependent absorption coefficients, refractive indices, and complex permittivities of pure ethanol and gasoline, and their mixtures at varying ethanol volume percentages (v/v %) are reported. As the mixing ratio changes, meaningful shifts are observed in the frequency dependent refractive index and absorption coefficients associated with the dominant component, ethanol. The relaxation dynamics of the pure gasoline and ethanol are successfully modeled with the Debye model using the ultrafast nature of the terahertz transients, and those of mixture solutions are investigated by an additive model with an assumption of minimum interaction due to the significant differences in their molecular natures; polar and nonpolar. Successful modeling of the mixtures confirms the weak interaction assumption and enables us to accurately determine the ethanol content. Among five ethanol/gasoline blends, except for one mixture, the estimated percent ethanol in gasoline is predicted with an accuracy of ca. 1% with respect to the actual ethanol percentage. In addition, the results show that free OH contribution to the macroscopic polarization is significantly higher at low concentrations (5-20%) and lower at 50% compared to the case of pure ethanol. The measurements and analysis presented here show that time domain terahertz studies can offer invaluable insight into development of new models for polar/nonpolar complex mixture solutions.
Collapse
Affiliation(s)
- Enis Arik
- Department of Chemistry, Middle East Technical University , Ankara 06800, Turkey
| | | | | |
Collapse
|
42
|
Sonnleitner T, Turton DA, Waselikowski S, Hunger J, Stoppa A, Walther M, Wynne K, Buchner R. Dynamics of RTILs: A comparative dielectric and OKE study. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2013.09.019] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
43
|
Fuchs A, Buchner R, Hefter G. Solvation and association of 3:1 electrolytes in N,N-dimethylformamide. J Phys Chem B 2013; 117:14468-76. [PMID: 24171442 DOI: 10.1021/jp4089436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A detailed study has been made of the solvation and ion association of the trifluoromethanesulfonate (Tf(-)) salts of aluminum(III), scandium(III), and lanthanum(III) in N,N-dimethylformamide (DMF) at 25 °C using dielectric relaxation spectroscopy over the frequency range of 0.1 ≲ ν/GHz ≤ 89. The spectra of all solutions exhibited either two (for ScTf3 and LaTf3) or three (for AlTf3) relaxation processes, a dominant mode centered at ∼15 GHz due to the solvent and one or (for AlTf3 solutions) two solute-related processes at lower frequencies (νmax ≲ 2 GHz). Effective solvation numbers, Zib, calculated from the solvent relaxation process indicated that all three cations were strongly solvated by DMF with Zib(0) values at infinite dilution in the order (Al(3+) ≈ Sc(3+) ≈ 10) < (La(3+) ≈ 13), consistent with at least partial formation of a second solvation shell around each cation. One solute-related mode for each set of salt solutions was assigned to the rotational diffusion of solvent-shared ion pairs (SIPs) of 1:1 stoicheometry; the additional slower process for AlTf3 solutions in DMF was attributed to the presence of double-solvent-separated IPs. The overall association constants at infinite dilution for the 1:1 IPs, KA°(MTf(2+)), were significant, but as expected from Debye-Hückel considerations, the KA values decreased rapidly with increasing solute concentration.
Collapse
Affiliation(s)
- Anna Fuchs
- Chemistry Department, Murdoch University , Murdoch, Western Australia 6150, Australia
| | | | | |
Collapse
|
44
|
Rahman HMA, Hefter G, Buchner R. Hydrophilic and Hydrophobic Hydration of Sodium Propanoate and Sodium Butanoate in Aqueous Solution. J Phys Chem B 2013; 117:2142-52. [DOI: 10.1021/jp310029c] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Hafiz M. A. Rahman
- Institut für Physikalische
und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| | - Glenn Hefter
- Chemistry Department, Murdoch University, Murdoch, WA 6150 Australia
| | - Richard Buchner
- Institut für Physikalische
und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| |
Collapse
|
45
|
Ion-pair or ion-cloud relaxation? On the origin of small-amplitude low-frequency relaxations of weakly associating aqueous electrolytes. J Mol Liq 2012. [DOI: 10.1016/j.molliq.2012.03.025] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
46
|
|
47
|
Son H, Jin H, Choi SR, Jung HW, Park S. Infrared Probing of Equilibrium and Dynamics of Metal–Selenocyanate Ion Pairs in N,N-Dimethylformamide Solutions. J Phys Chem B 2012; 116:9152-9. [DOI: 10.1021/jp304595n] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hyewon Son
- Department of Chemistry, Korea University, Seoul 136-701, Korea
| | - Haneul Jin
- Department of Chemistry, Korea University, Seoul 136-701, Korea
| | - Seung Ryul Choi
- Department of Chemistry, Korea University, Seoul 136-701, Korea
| | - Hyun Wook Jung
- Department of Chemical and Biological Engineering, Korea University, Seoul
136-713, Korea
| | - Sungnam Park
- Department of Chemistry, Korea University, Seoul 136-701, Korea
- Multidimensional
Spectroscopy
Laboratory, Korea Basic Science Institute, Seoul 136-713, Korea
| |
Collapse
|
48
|
Stoppa A, Hunger J, Hefter G, Buchner R. Structure and Dynamics of 1-N-Alkyl-3-N-Methylimidazolium Tetrafluoroborate + Acetonitrile Mixtures. J Phys Chem B 2012; 116:7509-21. [DOI: 10.1021/jp3020673] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Alexander Stoppa
- Institut für Physikalische
und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| | - Johannes Hunger
- Institut für Physikalische
und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| | - Glenn Hefter
- Chemistry Department, Murdoch University, Murdoch, WA 6150, Australia
| | - Richard Buchner
- Institut für Physikalische
und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| |
Collapse
|
49
|
Lohse PW, Bartels N, Stoppa A, Buchner R, Lenzer T, Oum K. Dielectric relaxation and ultrafast transient absorption spectroscopy of [C6mim]+[Tf2N]−/acetonitrile mixtures. Phys Chem Chem Phys 2012; 14:3596-603. [DOI: 10.1039/c2cp23704k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
50
|
Rahman HMA, Hefter G, Buchner R. Hydration of Formate and Acetate Ions by Dielectric Relaxation Spectroscopy. J Phys Chem B 2011; 116:314-23. [DOI: 10.1021/jp207504d] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Hafiz M. A. Rahman
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| | - Glenn Hefter
- Chemistry Department, Murdoch University, Murdoch, WA 6150, Australia
| | - Richard Buchner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, D-93040 Regensburg, Germany
| |
Collapse
|