1
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Gibb CD, Tran TH, Gibb BC. Assessing Weak Anion Binding to Small Peptides. J Phys Chem B 2024; 128:3605-3613. [PMID: 38592238 PMCID: PMC11033870 DOI: 10.1021/acs.jpcb.4c00657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/11/2024] [Accepted: 03/22/2024] [Indexed: 04/10/2024]
Abstract
Since Hofmeister's seminal studies in the late 19th century, it has been known that salts and buffers can drastically affect the properties of peptides and proteins. These Hofmeister effects can be conceived of in terms of three distinct phenomena/mechanisms: water-salt interactions that indirectly induce the salting-out of a protein by water sequestration by the salt, and direct salt-protein interactions that can either salt-in or salt-out the protein. Unfortunately, direct salt-protein interactions responsible for Hofmeister effects are weak and difficult to quantify. As such, they are frequently construed of as being nonspecific. Nevertheless, there has been considerable effort to better specify these interactions. Here, we use pentapeptides to demonstrate the utility of the H-dimension of nuclear magnetic resonance (NMR) spectroscopy to assess anion binding using N-H signal shifts. We qualify binding using these, demonstrating the upfield shifts induced by anion association and revealing how they are much larger than the corresponding downfield shifts induced by magnetic susceptibility and other ionic strength change effects. We also qualify binding in terms of how the pattern of signal shifts changes with point mutations. In general, we find that the observed upfield shifts are small compared with those induced by anion binding to amide-based hosts, and MD simulations suggest that this is so. Thus, charge-diffuse anions associate mostly with the nonpolar regions of the peptide rather than directly interacting with the amide N-H groups. These findings reveal the utility of 1H NMR spectroscopy for qualifying affinity to peptides─even when affinity constants are very low─and serve as a benchmark for using NMR spectroscopy to study anion binding to more complex systems.
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Affiliation(s)
- Corinne
L. D. Gibb
- Department of Chemistry, Tulane University School of Science and Engineering, New Orleans, Louisiana 70118, United States
| | - Thien H. Tran
- Department of Chemistry, Tulane University School of Science and Engineering, New Orleans, Louisiana 70118, United States
| | - Bruce C. Gibb
- Department of Chemistry, Tulane University School of Science and Engineering, New Orleans, Louisiana 70118, United States
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2
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Donon J, Bardaud JX, Brenner V, Ishiuchi SI, Fujii M, Gloaguen E. Stepwise dissociation of ion pairs by water molecules: cation-dependent separation mechanisms between carboxylate and alkali-earth metal ions. Phys Chem Chem Phys 2022; 24:12121-12125. [PMID: 35545953 DOI: 10.1039/d2cp01158a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microhydrated H2-tagged ion pairs (Ca2+, AcO-)(H2O)n=0-8 and (Ba2+, AcO-)(H2O)n=0-5 are investigated by IR photodissociation laser spectroscopy and DFT-D frequency calculations. The detailed picture of the first steps of ion dissociation reveals two mechanisms, where water molecules promote dissociation either directly or indirectly depending on the nature of the cation.
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Affiliation(s)
- Jeremy Donon
- LIDYL, CEA, CNRS, Université Paris Saclay CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Jean-Xavier Bardaud
- LIDYL, CEA, CNRS, Université Paris Saclay CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Valérie Brenner
- LIDYL, CEA, CNRS, Université Paris Saclay CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Shun-Ichi Ishiuchi
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
| | - Masaaki Fujii
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
| | - Eric Gloaguen
- LIDYL, CEA, CNRS, Université Paris Saclay CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
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3
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Donon J, Habka S, Very T, Charnay-Pouget F, Mons M, Aitken DJ, Brenner V, Gloaguen E. Ion Pair Supramolecular Structure Identified by ATR-FTIR Spectroscopy and Simulations in Explicit Solvent*. Chemphyschem 2021; 22:2442-2455. [PMID: 34637180 DOI: 10.1002/cphc.202100565] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/17/2021] [Indexed: 11/12/2022]
Abstract
The present work uses ATR-FTIR spectroscopy assisted by simulations in explicit solvent and frequency calculations to investigate the supramolecular structure of carboxylate alkali-metal ion pairs in aqueous solutions. ATR-FTIR spectra in the 0.25-4.0 M concentration range displayed cation-specific behaviors, which enabled the measurement of the appearance concentration thresholds of contact ion pairs between 1.9 and 2.6 M depending on the cation. Conformational explorations performed using a non-local optimization method associated to a polarizable force-field (AMOEBA), followed by high quantum chemistry level (RI-B97-D3/dhf-TZVPP) optimizations, mode-dependent scaled harmonic frequency calculations and electron density analyses, were used to identify the main supramolecular structures contributing to the experimental spectra. A thorough analysis enables us to reveal the mechanisms responsible for the spectroscopic sensitivity of the carboxylate group and the respective role played by the cation and the water molecules, highlighting the necessity of combining advanced experimental and theoretical techniques to provide a fair and accurate description of ion pairing.
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Affiliation(s)
- Jeremy Donon
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191, Gif-sur-Yvette, France
| | - Sana Habka
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191, Gif-sur-Yvette, France
| | - Thibaut Very
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191, Gif-sur-Yvette, France.,IDRIS-CNRS, Campus Universitaire d'Orsay, BP 167, 91403, Orsay cedex, France
| | - Florence Charnay-Pouget
- ICMMO, CNRS, Université Paris Sud, Université Paris Saclay, UMR 8182, Bât. 420, 15 rue Georges Clémenceau, 91405, Orsay cedex, France.,Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, 63000, Clermont-Ferrand, France
| | - Michel Mons
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191, Gif-sur-Yvette, France
| | - David J Aitken
- ICMMO, CNRS, Université Paris Sud, Université Paris Saclay, UMR 8182, Bât. 420, 15 rue Georges Clémenceau, 91405, Orsay cedex, France
| | - Valérie Brenner
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191, Gif-sur-Yvette, France
| | - Eric Gloaguen
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191, Gif-sur-Yvette, France
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4
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He H, Liu Z, Chen S, He X, Wang X, Wang X. Active Role of Water in the Hydration of Macromolecules with Ionic End Group for Hydrophobic Effect-Caused Assembly. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00683] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Huiwen He
- College of Materials Science and Engineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, China
| | - Zhen Liu
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Si Chen
- College of Materials Science and Engineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, China
| | - Xiaohua He
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Xu Wang
- College of Materials Science and Engineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, China
| | - Xiaosong Wang
- Waterloo Institute for Nanotechnology and Department of Chemistry, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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5
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Habka S, Very T, Donon J, Vaquero-Vara V, Tardivel B, Charnay-Pouget F, Mons M, Aitken DJ, Brenner V, Gloaguen E. Identification of ion pairs in solution by IR spectroscopy: crucial contributions of gas phase data and simulations. Phys Chem Chem Phys 2019; 21:12798-12805. [PMID: 30977483 DOI: 10.1039/c9cp00700h] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In a context where structure elucidation of ion pairs in solution remains a contemporary challenge, this work explores an original approach where accurate gas phase spectroscopic data are used to refine high level quantum chemistry calculations of ion pairs in solution, resulting in an unprecedented level of accuracy in vibrational frequency prediction. First, gas phase studies focus on a series of isolated contact ion pairs (M+, Ph-CH2-COO-, with M = Li, Na, K, Rb, Cs) for which conformer-selective IR spectra in the CO2- stretch region are recorded. These experiments reveal the interactions at play in isolated contact ion pairs, and provide vibrational frequencies enabling us to assess the accuracy of the theoretical approach used, i.e., mode-dependent scaled harmonic frequency calculations at the RI-B97-D3/dhf-TZVPP level. This level of calculation is then employed on large water clusters embedding either a free acetate ion or its contact or solvent-shared pairs with a sodium cation in order to simulate the individual vibrational spectra of these species in solution. This study shows that the stretching modes of carboxylate are sensitive to both solvent-shared and contact ion pair formation. FTIR spectra of solutions of increasing concentrations indeed reveal several spectral changes consistent with the presence of specific types of solvent-shared and contact ion pairs. By providing relevant guidelines for the interpretation of solution phase IR spectra, this work illustrates the potential of the approach for the elucidation of supramolecular structures in electrolyte solutions.
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Affiliation(s)
- Sana Habka
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Thibaut Very
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Jeremy Donon
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Vanesa Vaquero-Vara
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Benjamin Tardivel
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Florence Charnay-Pouget
- ICMMO, CNRS, Université Paris Sud, Université Paris Saclay, UMR 8182, Bât. 420, 15 rue Georges Clémenceau, 91405 Orsay cedex, France
| | - Michel Mons
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - David J Aitken
- ICMMO, CNRS, Université Paris Sud, Université Paris Saclay, UMR 8182, Bât. 420, 15 rue Georges Clémenceau, 91405 Orsay cedex, France
| | - Valérie Brenner
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
| | - Eric Gloaguen
- LIDYL, CEA, CNRS, Université Paris Saclay, CEA Saclay, Bât 522, 91191 Gif-sur-Yvette, France.
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6
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Schwaab G, Sebastiani F, Havenith M. Untersuchung von Ionenhydratation und Ionenpaarbildung mittels THz‐Spektroskopie. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201805261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum 44780 Bochum Deutschland
| | - Federico Sebastiani
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum 44780 Bochum Deutschland
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum 44780 Bochum Deutschland
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7
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Schwaab G, Sebastiani F, Havenith M. Ion Hydration and Ion Pairing as Probed by THz Spectroscopy. Angew Chem Int Ed Engl 2018; 58:3000-3013. [PMID: 30022575 DOI: 10.1002/anie.201805261] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/17/2018] [Indexed: 11/12/2022]
Abstract
Ion hydration is of pivotal importance for many fundamental processes. Various spectroscopic methods are used to study the retardation of the hydration bond dynamics in the vicinity of anions and cations. Here we introduce THz-FTIR spectroscopy as a powerful method to answer the open questions. We show through dissection of THz spectra that we can pinpoint characteristic absorption features that can be attributed to the rattling modes of strongly hydrating ions within their hydration cages as well as vibrationally induced charge fluctuations in the case of weakly hydrating ions. Further analysis yields information on anion-cation cooperativity, the size of the dynamic hydration shell, as well as the lifetimes of these collective ion-hydration water modes and their connecting thermal bath states. Our study provides evidence for a non-additive behavior, thus questioning the simplified Hofmeister model. THz spectroscopy enables ion pairing to be observed and quantified at a high salt concentration.
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Affiliation(s)
- Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Federico Sebastiani
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
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8
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Sullivan MR, Yao W, Tang D, Ashbaugh HS, Gibb BC. The Thermodynamics of Anion Complexation to Nonpolar Pockets. J Phys Chem B 2018; 122:1702-1713. [PMID: 29373793 PMCID: PMC10668596 DOI: 10.1021/acs.jpcb.7b12259] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The interactions between nonpolar surfaces and polarizable anions lie in a gray area between the hydrophobic and Hofmeister effects. To assess the affinity of these interactions, NMR and ITC were used to probe the thermodynamics of eight anions binding to four different hosts whose pockets each consist primarily of hydrocarbon. Two classes of host were examined: cavitands and cyclodextrins. For all hosts, anion affinity was found to follow the Hofmeister series, with associations ranging from 1.6-5.7 kcal mol-1. Despite the fact that cavitand hosts 1 and 2 possess intrinsic negative electrostatic fields, it was determined that these more enveloping hosts generally bound anions more strongly. The observation that the four hosts each possess specific anion affinities that cannot be readily explained by their structures, points to the importance of counter cations and the solvation of the "empty" hosts, free guests, and host-guest complexes, in defining the affinity.
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Affiliation(s)
- Matthew R. Sullivan
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, United States
| | - Wei Yao
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, United States
| | - Du Tang
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States
| | - Henry S Ashbaugh
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States
| | - Bruce C. Gibb
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, United States
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9
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Wang XB. Cluster Model Studies of Anion and Molecular Specificities via Electrospray Ionization Photoelectron Spectroscopy. J Phys Chem A 2017; 121:1389-1401. [PMID: 28060511 DOI: 10.1021/acs.jpca.6b09784] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Ion specificity, a widely observed macroscopic phenomenon in condensed phases and at interfaces, is a fundamental chemical physics issue. Herein we report our recent studies of such effects using cluster models in an "atom-by-atom" and "molecule-by-molecule" fashion not possible with the condensed-phase methods. We use electrospray ionization (ESI) to generate molecular and ionic clusters to simulate key molecular entities involved in local binding regions and characterize them by employing negative ion photoelectron spectroscopy (NIPES). Inter- and intramolecular interactions and binding configurations are directly obtained as functions of the cluster size and composition, providing molecular-level descriptions and characterization over the local active sites that play crucial roles in determining the solution chemistry and condensed-phase phenomena. The topics covered in this article are relevant to a wide range of research fields from ion specific effects in electrolyte solutions, ion selectivity/recognition in normal functioning of life, to molecular specificity in aerosol particle formation, as well as in rational material design and synthesis.
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Affiliation(s)
- Xue-Bin Wang
- Physical Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, MS K8-88, Richland, Washington 99352, United States
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10
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Habka S, Brenner V, Mons M, Gloaguen E. Gas-Phase Spectroscopic Signatures of Carboxylate-Li(+) Contact Ion Pairs: New Benchmarks For Characterizing Ion Pairing in Solution. J Phys Chem Lett 2016; 7:1192-1197. [PMID: 26978595 DOI: 10.1021/acs.jpclett.6b00454] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The coexistence of several types of ion pairs in solution together with their elusive nature hampers their experimental characterization, which relies in practice on theoretical models resorting to numerous approximations. In this context, a series of isolated contact ion pairs between a lithium cation and phenyl-tagged carboxylate anions of various lengths (Ph-(CH2)n-COO(-), n = 1-3) has been investigated in a conformer-selective manner by IR and UV laser spectroscopy, in conjunction with quantum chemistry calculations. The typical gas-phase IR signature of the bidentate structure formed between the carboxylate moiety and Li(+) has thus been obtained in the CO2(-) stretch region. In addition to the cation-anion interaction, a cation-π interaction occurs simultaneously in the largest system investigated (n = 3). The resulting distorted ion pair structure has been evidenced from both the IR signature of the CO2(-) stretches and the unique vibrationally resolved UV spectroscopy of a phenyl ring interacting with a cation. Such specific spectroscopic signatures of contact ion pairs provide experimental benchmarks, alternative to theoretical predictions, that can assist the assignment of vibrational spectra in solution.
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Affiliation(s)
- Sana Habka
- LIDYL, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Valérie Brenner
- LIDYL, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Michel Mons
- LIDYL, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Eric Gloaguen
- LIDYL, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette, France
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11
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Wang Y, Bowman JM, Kamarchik E. Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions. J Chem Phys 2016; 144:114311. [DOI: 10.1063/1.4943580] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yimin Wang
- Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Joel M. Bowman
- Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
| | - Eugene Kamarchik
- Quantum Pomegranate, LLC, 2604 Kings Lake Court NE, Atlanta, Georgia 30345, USA
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12
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Affiliation(s)
- Wen Jun Xie
- Institute of Theoretical
and Computational Chemistry, College of Chemistry and Molecular Engineering,
Beijing National Laboratory of Molecular Sciences, and Biodynamic
Optical Imaging Center, Peking University, Beijing 100871, China
| | - Zhen Zhang
- Institute of Theoretical
and Computational Chemistry, College of Chemistry and Molecular Engineering,
Beijing National Laboratory of Molecular Sciences, and Biodynamic
Optical Imaging Center, Peking University, Beijing 100871, China
| | - Yi Qin Gao
- Institute of Theoretical
and Computational Chemistry, College of Chemistry and Molecular Engineering,
Beijing National Laboratory of Molecular Sciences, and Biodynamic
Optical Imaging Center, Peking University, Beijing 100871, China
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13
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Allolio C, Baxova K, Vazdar M, Jungwirth P. Guanidinium Pairing Facilitates Membrane Translocation. J Phys Chem B 2015; 120:143-53. [DOI: 10.1021/acs.jpcb.5b10404] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Christoph Allolio
- Institute
of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic
- Institut
für Physikalische and Theoretische Chemie, Universität Regensburg, 93040 Regensburg, Germany
| | - Katarina Baxova
- Institute
of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic
| | - Mario Vazdar
- Institut
Rudjer
Bošković, Bijenička
cesta 54, 10000 Zagreb, Croatia
| | - Pavel Jungwirth
- Institute
of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic
- Department
of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
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14
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Perera GS, Nettles CB, Zhou Y, Zou S, Hollis TK, Zhang D. Direct Observation of Ion Pairing at the Liquid/Solid Interfaces by Surface Enhanced Raman Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:8998-9005. [PMID: 26258255 DOI: 10.1021/acs.langmuir.5b01903] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ion-pairing, the association of oppositely charged ionic species in solution and at liquid/solid interfaces has been proposed as a key factor for a wide range of physicochemical phenomena. However, experimental observations of ion pairing at the ligand/solid interfaces are challenging due to difficulties in differentiating ion species in the electrical double layer from that adsorbed on the solid surfaces. Using surface enhanced Raman spectroscopy in combination with electrolyte washing, we presented herein the first direct experimental evidence of ion pairing, the coadsorption of oppositely charged ionic species onto gold nanoparticles (AuNPs). Ion pairing reduces the electrolyte concentration threshold in inducing AuNP aggregation and enhances the competitiveness of electrolyte over neutral molecules for binding to AuNP surfaces. The methodology and insights provided in this work should be important for understanding electrolyte interfacial interactions with nanoparticles.
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Affiliation(s)
- Ganganath S Perera
- Department of Chemistry, Mississippi State University , Mississippi State, Mississippi 39762, United States
| | - Charles B Nettles
- Department of Chemistry, Mississippi State University , Mississippi State, Mississippi 39762, United States
| | - Yadong Zhou
- Department of Chemistry, University of Central Florida , Orlando, Florida 32816, United States
| | - Shengli Zou
- Department of Chemistry, University of Central Florida , Orlando, Florida 32816, United States
| | - T Keith Hollis
- Department of Chemistry, Mississippi State University , Mississippi State, Mississippi 39762, United States
| | - Dongmao Zhang
- Department of Chemistry, Mississippi State University , Mississippi State, Mississippi 39762, United States
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15
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Lee SS, Jadhav VH, Kim JY, Chun JH, Lee A, Kim SY, Lee S, Kim DW. Quantum chemical investigation of the origin of activation of SN2 type halogenation by oligo-ethylene glycol—ionic liquids. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.03.074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Ghosh MK, Choi TH, Choi CH. Like-charge ion pairs of hydronium and hydroxide in aqueous solution? Phys Chem Chem Phys 2015; 17:16233-7. [DOI: 10.1039/c5cp02182k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydroxide can form stronger like-ion pairs than hydronium in aqueous solution mostly due to its versatile coordination ability with solvents.
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Affiliation(s)
- Manik Kumer Ghosh
- Department of Chemistry and Green-Nano Materials Research Center
- College of Natural Sciences
- Kyungpook National University
- Daegu 702-701
- South Korea
| | - Tae Hoon Choi
- Department of Chemical Engineering Education
- Chungnam National University
- Daejeon 305-764
- Republic of Korea
| | - Cheol Ho Choi
- Department of Chemistry and Green-Nano Materials Research Center
- College of Natural Sciences
- Kyungpook National University
- Daegu 702-701
- South Korea
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17
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Sharma V, Böhm F, Schwaab G, Havenith M. The low frequency motions of solvated Mn(ii) and Ni(ii) ions and their halide complexes. Phys Chem Chem Phys 2014; 16:25101-10. [DOI: 10.1039/c4cp03989k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Concentration dependent THz/FIR absorption measurements allow determination of individual solvated ion resonances and their influence on the hydration water spectrum.
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Affiliation(s)
- Vinay Sharma
- Physical Chemistry 2
- Ruhr-Universität Bochum
- Universitätsstraße 150
- Bochum, Germany
| | - Fabian Böhm
- Physical Chemistry 2
- Ruhr-Universität Bochum
- Universitätsstraße 150
- Bochum, Germany
| | - Gerhard Schwaab
- Physical Chemistry 2
- Ruhr-Universität Bochum
- Universitätsstraße 150
- Bochum, Germany
| | - Martina Havenith
- Physical Chemistry 2
- Ruhr-Universität Bochum
- Universitätsstraße 150
- Bochum, Germany
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