1
|
O’Brien MH, Ranganathan R, Merunka D, Stafford AK, Bleecker SD, Peric M. Effect of Charge on the Rotation of Prolate Nitroxide Spin Probes in Room-Temperature Ionic Liquids. J Mol Liq 2024; 404:124994. [PMID: 38855052 PMCID: PMC11155483 DOI: 10.1016/j.molliq.2024.124994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
We have studied the rotational diffusion of two prolate nitroxide probes, the doubly negatively charged peroxylamine disulfonate (Frémy's salt - FS) and neutral di-tert-butyl nitroxide (DTBN), in a series of 1-alkyl-3-methylimidazolium tetrafluoroborate room-temperature ionic liquids (RTILs) having alkyl chain lengths from two to eight carbons using electron paramagnetic resonance (EPR) spectroscopy. Though the size and shape of the probes are reasonably similar, they behave differently due to the charge difference. The rotation of FS is anisotropic, and the rotational anisotropy increases with the alkyl chain length of the cation, while the rotation of DTBN is isotropic. The hyperfine coupling constant of DTBN decreases as a function of the alkyl chain length and is proportional to the relative permittivity of ionic liquids. On the other hand, the hyperfine coupling constant of FS increases with increasing chain length. These behaviors indicate the location of each probe in RTILs. FS is likely located in the polar region near the network of charged imidazolium ions. DTBN molecules are predominately distributed in the nonpolar domains.
Collapse
Affiliation(s)
- Meghan H. O’Brien
- Department of Physics and Astronomy, California State University, Northridge, Northridge, California 91330, United States
| | - Radha Ranganathan
- Department of Physics and Astronomy, California State University, Northridge, Northridge, California 91330, United States
| | - Dalibor Merunka
- Division of Physical Chemistry, Ruđer Bošković Institute, Bijenička cesta 54, HR-10000 Zagreb, Croatia
| | - Alexander K. Stafford
- Department of Physics and Astronomy, California State University, Northridge, Northridge, California 91330, United States
| | - Steven D. Bleecker
- Department of Physics and Astronomy, California State University, Northridge, Northridge, California 91330, United States
| | - Miroslav Peric
- Department of Physics and Astronomy, California State University, Northridge, Northridge, California 91330, United States
| |
Collapse
|
2
|
Mukherjee K, Palchowdhury S, Maroncelli M. Do Electrostatics Control the Diffusive Dynamics of Solitary Water? NMR and MD Studies of Water Translation and Rotation in Dipolar and Ionic Solvents. J Phys Chem B 2024; 128:3689-3706. [PMID: 38588535 DOI: 10.1021/acs.jpcb.3c08300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
NMR-based measurements of the diffusion coefficients and rotation times of solitary water and benzene at 300 K are reported in a diverse collection of 13 conventional organic solvents and 10 imidazolium ionic liquids. Proton chemical shifts of water are found to be correlated to water OH-stretching frequencies, confirming the importance of electrostatic interactions in these shifts. However, the influence of magnetic interactions in aromatic solvents renders chemical shifts a less reliable indicator of electrostatics. Diffusion coefficients (DB) and rotational correlation times (τB) of benzene in the solvents examined are accurately described as functions of viscosity (η) by DB ∝ η-0.81 and τB ∝ η0.64. Literature values of DB and τB in alkane and normal alcohols, which were not included among the solvents studied here, are systematically faster than predicted by these correlations, indicating that factors beyond solvent viscosity play a role in determining the friction on benzene. In contrast to benzene, water diffusion and rotation are poorly described in terms of viscosity alone, even in the dipolar and ionic solvents measured here. The present data and the substantial literature data already available on dilute water diffusion show a systematic dependence of DW on solvent polarity among isoviscous solvents. The aspect of solvent polarity most relevant to water dynamics is the ability of a solvent to accept hydrogen bonds from water, as conveniently quantified by the frequency of water's OH stretching band, ΔνOH. The friction on translation, ζtr = kBT/DW, and rotation, ζrot = kBTτW, are both well correlated by functions of the form ζ(η, ΔνOH) = a1ηa2 exp (a3ΔνOH), where the ai are adjustable parameters. Molecular dynamics simulations reveal a strong coupling between electrostatic and nonelectrostatic water-solvent interactions, which makes it impossible to dissect the friction on water into additive dielectric and hydrodynamic components. Simulations also provide a tentative explanation for the unusual form of the correlating function ζ(η, ΔνOH), at least in the case of ζrot.
Collapse
Affiliation(s)
- Kallol Mukherjee
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Sourav Palchowdhury
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mark Maroncelli
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|
3
|
Fujii K, Kimura Y. Solvent Role of Ionic Liquids in Fundamental Chemical Reaction Dynamics Analyzed by Time-Resolved Spectroscopy. CHEM REC 2023; 23:e202200242. [PMID: 36634996 DOI: 10.1002/tcr.202200242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/24/2022] [Indexed: 01/14/2023]
Abstract
Ionic liquids (ILs), which are used as solvents for chemical reactions, are different from conventional organic solvents owing to their designability. Physicochemical parameters of the ILs, such as polarity and viscosity, that affect chemical equilibria and reaction kinetics can be tuned by changing the combination of anions and cations or by varying the lengths of the alkyl chains present in the cations. We were interested in knowing how these physicochemical parameters affect fundamental chemical reactions in ILs. Therefore, in this personal account, we investigate our recent work on two different photochemical reactions in ILs, namely excited-state intramolecular proton transfer of hydroxyflavone and photodissociation of aminodisulfide, using time-resolved spectroscopic techniques. Interestingly, the roles of the ILs in these chemical reactions are quite different. The effect of the cationic species of the ILs (i. e., the head groups and number of alkyl carbons) on the solvation environment upon photoexcitation and reaction rate are discussed.
Collapse
Affiliation(s)
- Kaori Fujii
- Faculty of Science and Engineering, Doshisha University, Kyotanabe-city, Kyoto 610-0321, Japan
| | - Yoshifumi Kimura
- Graduate School of Science and Engineering, Faculty of Science and Engineering, Doshisha University, Kyotanabe-city, Kyoto 610-0321, Japan
| |
Collapse
|
4
|
Fraenza CC, Greenbaum SG, Suarez SN. Nuclear Magnetic Resonance Relaxation Pathways in Electrolytes for Energy Storage. Int J Mol Sci 2023; 24:10373. [PMID: 37373520 PMCID: PMC10299207 DOI: 10.3390/ijms241210373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Nuclear Magnetic Resonance (NMR) spin relaxation times have been an instrumental tool in deciphering the local environment of ionic species, the various interactions they engender and the effect of these interactions on their dynamics in conducting media. Of particular importance has been their application in studying the wide range of electrolytes for energy storage, on which this review is based. Here we highlight some of the research carried out on electrolytes in recent years using NMR relaxometry techniques. Specifically, we highlight studies on liquid electrolytes, such as ionic liquids and organic solvents; on semi-solid-state electrolytes, such as ionogels and polymer gels; and on solid electrolytes such as glasses, glass ceramics and polymers. Although this review focuses on a small selection of materials, we believe they demonstrate the breadth of application and the invaluable nature of NMR relaxometry.
Collapse
Affiliation(s)
- Carla C. Fraenza
- Physics Department, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA; (C.C.F.); (S.G.G.)
| | - Steve G. Greenbaum
- Physics Department, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA; (C.C.F.); (S.G.G.)
- Physics Department, The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
| | - Sophia N. Suarez
- Physics Department, The Graduate Center, City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- Physics Department, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
| |
Collapse
|
5
|
Gimbal-Zofka Y, Karg B, Dziubinska-Kühn K, Kowalska M, Wesolowski TA, Rumble CA. Simulations of electric field gradient fluctuations and dynamics around sodium ions in ionic liquids. J Chem Phys 2022; 157:244502. [PMID: 36586985 DOI: 10.1063/5.0126693] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The T1 relaxation time measured in nuclear magnetic resonance experiments contains information about electric field gradient (EFG) fluctuations around a nucleus, but computer simulations are typically required to interpret the underlying dynamics. This study uses classical molecular dynamics (MD) simulations and quantum chemical calculations, to investigate EFG fluctuations around a Na+ ion dissolved in the ionic liquid 1-ethyl 3-methylimidazolium tetrafluoroborate, [Im21][BF4], to provide a framework for future interpretation of NMR experiments. Our calculations demonstrate that the Sternheimer approximation holds for Na+ in [Im21][BF4], and the anti-shielding coefficient is comparable to its value in water. EFG correlation functions, CEFG(t), calculated using quantum mechanical methods or from force field charges are roughly equivalent after 200 fs, supporting the use of classical MD for estimating T1 times of monatomic ions in this ionic liquid. The EFG dynamics are strongly bi-modal, with 75%-90% of the de-correlation attributable to inertial solvent motion and the remainder to a highly distributed diffusional processes. Integral relaxation times, ⟨τEFG⟩, were found to deviate from hydrodynamic predictions and were non-linearly coupled to solvent viscosity. Further investigation showed that Na+ is solvated by four tetrahedrally arranged [BF4]- anions and directly coordinated by ∼6 fluorine atoms. Exchange of [BF4]- anions is rare on the 25-50 ns timescale and suggests that motion of solvent-shell [BF4]- is the primary mechanism for the EFG fluctuations. Different couplings of [BF4]- translational and rotational diffusion to viscosity are shown to be the source of the non-hydrodynamic scaling of ⟨τEFG⟩.
Collapse
Affiliation(s)
- Yann Gimbal-Zofka
- Départment de Chimie Physique, Université de Genève, 30, quai Ernest-Ansermet, CH-1211 Genève 4, Switzerland
| | - Beatrice Karg
- Département de Physique Nucléaire et Corpusculaire, Université de Genève, CH-1211 Genève 4, Switzerland
| | | | | | - Tomasz A Wesolowski
- Départment de Chimie Physique, Université de Genève, 30, quai Ernest-Ansermet, CH-1211 Genève 4, Switzerland
| | - Christopher A Rumble
- The Pennsylvania State University - Altoona College, 3000 Ivyside Park, Altoona, Pennsylvania 16601, USA
| |
Collapse
|
6
|
Structural Anomaly in Glasses: Molecular Dynamics Study of Organic Radical in Dibutylphthalate at Different Temperatures. Int J Mol Sci 2022; 23:ijms232314859. [PMID: 36499187 PMCID: PMC9735606 DOI: 10.3390/ijms232314859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022] Open
Abstract
Understanding the heterogeneous nano/microscopic structures of various organic glasses is fundamental and necessary for many applications. Recently, unusual structural phenomena have been observed experimentally in various organic glasses near their glass transition temperatures (Tg), including dibutyl phthalate (DBP). In particular, the librational motion of radical probe in the glass is progressively suppressed upon temperature increase. In this work, we report in-depth molecular dynamics studies of structural anomalies in DBP glass, that revealed insights into the general mechanism of these phenomena. In particular, we have evidenced that the two types of solvation within alkyl chains coexist, allowing only small-angle wobbling of the solute molecule (TEMPO radical), and another favouring large-angle rotations. The former solvation assumes constrained location of the solute near carboxyl groups of DBP, while the latter is coupled to the concerted movement of butyl chains. Remarkably, excellent qualitative and quantitative agreement with previous experimental results were obtained. As such, we are certain that the above-mentioned dynamic phenomena explain the intriguing structural anomalies observed in DBP and some other glasses in the vicinity of Tg.
Collapse
|
7
|
Damodaran K. Recent advances in NMR spectroscopy of ionic liquids. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 129:1-27. [PMID: 35292132 DOI: 10.1016/j.pnmrs.2021.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/17/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
This review presents recent developments in the application of NMR spectroscopic techniques in the study of ionic liquids. NMR has been the primary tool not only for the structural characterization of ionic liquids, but also for the study of dynamics. The presence of a host of NMR active nuclei in ionic liquids permits widespread use of multinuclear NMR experiments. Chemical shifts and multinuclear coupling constants are used routinely for the structure elucidation of ionic liquids and of products formed by their covalent interactions with other materials. Also, the availability of a multitude of NMR techniques has facilitated the study of dynamical processes in them. These include the use of NOESY to study inter-ionic interactions, pulsed-field gradient techniques for probing transport properties, and relaxation measurements to elucidate rotational dynamics. This review will focus on the application of each of these techniques to investigate ionic liquids.
Collapse
Affiliation(s)
- Krishnan Damodaran
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, United States.
| |
Collapse
|
8
|
Rumble CA, Vauthey E. Molecular Dynamics Simulations of Bimolecular Electron Transfer: the Distance-Dependent Electronic Coupling. J Phys Chem B 2021; 125:10527-10537. [PMID: 34519508 DOI: 10.1021/acs.jpcb.1c05013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Understanding the distance dependence of the parameters underpinning Marcus theory is imperative when interpreting the results of experiments on electron transfer (ET). Unfortunately, most of these parameters are difficult or impossible to access directly with experiments, necessitating the use of computer simulations to model them. In this work, we use molecular dynamics simulations in conjunction with constrained density functional theory calculations to study the distance dependence of the electronic coupling matrix element, |HRP|, for bimolecular ET. Contrary to what is typically assumed for such intermolecular reactions, we find that the magnitude of |HRP| does not decay exponentially with the center-of-mass separation of the reactants, rCOM. The addition of other simple measures of donor/acceptor (D/A) orientation did not improve the correlation of |HRP| with rCOM. Using the minimum distance separation, rmin, of the reactants as the structural descriptor allowed the system to be partitioned into high-coupling/close-contact and low-coupling/non-contact regimes, but large fluctuations of |HRP| were still found for the close-contact reactant pairs. Despite the persistent large fluctuations of |HRP|, its mean value was found to decay piecewise exponentially with increasing rmin, which was attributed to significant changes in the average D/A pair structure. The results herein advise one to use caution when interpreting the experimental results derived from spherical reactant models of bimolecular ET.
Collapse
Affiliation(s)
- Christopher A Rumble
- Départment de Chimie Physique, Université de Genève, 30 Quai Ernest-Ansermet, CH-1211 Genève 4, Switzerland
| | - Eric Vauthey
- Départment de Chimie Physique, Université de Genève, 30 Quai Ernest-Ansermet, CH-1211 Genève 4, Switzerland
| |
Collapse
|
9
|
Slade J, Merunka D, Huerta E, Peric M. Rotation of a Charged Spin Probe in Room-Temperature Ionic Liquids. J Phys Chem B 2021; 125:7435-7446. [PMID: 34197101 DOI: 10.1021/acs.jpcb.1c02471] [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
X-band electron paramagnetic resonance spectroscopy has been used to investigate the rotational diffusion of a stable, positively charged nitroxide 4-trimethylammonium-2,2,6,6-tetramethylpiperidine-1-oxyl iodide (Cat-1) in a series of 1-alkyl-3-methylimidazolium tetrafluoroborate room-temperature ionic liquids (RTILs) having alkyl chain lengths from two to eight carbons. The rotation of Cat-1 is anisotropic with the preferential axis of rotation along the NO• moiety. The Stokes-Einstein-Debye law describes the mean rotational correlation time of Cat-1, assuming that the hydrodynamic radius is smaller than the van der Waals radius of the probe. This implies that the probe rotates freely, experiencing slip boundary condition, which is solvent-dependent. The rotational correlation time of Cat-1 in RTILs can very well be fitted to a power-law functionality with a singular temperature, which suggests that the apparent activation energy of rotation exhibits non-Arrhenius behavior. Compared to the rotation of perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDTO), which is neutral, the rotation of Cat-1 is several times slower. The rotational anisotropy, the ratio of the rotational times of pDTO and Cat-1, and the apparent activation energy indicate the transition from a homogeneously globular structure to a spongelike structure when the alkyl chain has four carbons, which is also observed in molecular dynamics computational studies. For the first time, we have been able to show that the rotational correlation time of a solute molecule can be analyzed in terms of the Cohen-Turnbull free volume theory. The Cohen-Turnbull theory fully describes the rotation of Cat-1 in all ionic liquids in the measured temperature range.
Collapse
Affiliation(s)
- Jakov Slade
- Division of Physical Chemistry, Rud̵er Bošković Institute, Bijenička cesta 54, Zagreb HR-10000, Croatia
| | - Dalibor Merunka
- Division of Physical Chemistry, Rud̵er Bošković Institute, Bijenička cesta 54, Zagreb HR-10000, Croatia
| | - Ezequiel Huerta
- Department of Physics and Astronomy and The Center for Biological Physics, California State University, Northridge, Northridge, California 91330, United States
| | - Miroslav Peric
- Department of Physics and Astronomy and The Center for Biological Physics, California State University, Northridge, Northridge, California 91330, United States
| |
Collapse
|
10
|
Zhu H, O'Dell LA. Nuclear magnetic resonance characterisation of ionic liquids and organic ionic plastic crystals: common approaches and recent advances. Chem Commun (Camb) 2021; 57:5609-5625. [PMID: 34048516 DOI: 10.1039/d1cc02151f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic liquids, and their solid-state equivalents organic ionic plastic crystals, show many useful and tailorable properties that make them interesting for a wide range of applications including as electrolytes for energy storage devices. Nuclear magnetic resonance spectroscopy and related techniques offer a powerful and versatile toolkit for the characterisation of structure, interactions and dynamics in these materials. This article summarises both commonly used methods and some recent advances in this area, including solution- and solid-state methods, dynamic nuclear polarisation, imaging, diffusion and relaxation measurements, and example applications of some less commonly studied nuclei.
Collapse
Affiliation(s)
- Haijin Zhu
- Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Victoria 3220, Australia.
| | - Luke A O'Dell
- Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Victoria 3220, Australia.
| |
Collapse
|
11
|
Amith WD, Araque JC, Margulis CJ. Relationship between the Relaxation of Ionic Liquid Structural Motifs and That of the Shear Viscosity. J Phys Chem B 2021; 125:6264-6271. [PMID: 34097825 PMCID: PMC8279556 DOI: 10.1021/acs.jpcb.1c03105] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
In a set of recent
articles, we have highlighted that friction
is highly inhomogeneous in a typical ionic liquid (IL) with charge
networks that are stiff and charge-depleted regions that are soft.
This has consequences not only for the dynamics of ILs but also for the transport properties of solutes
dissolved in them. In this article, we explore whether the family
of alkylimidazolium ILs coupled with bis(trifluoromethylsulfonyl)imide
(with similar Coulombic interactions but different alkyl tails), when
dynamically “equalized” by having a similar shear viscosity,
display q-dependent structural relaxation time scales
that are the same across the family. Our results show that this is
not the case, and in fact, the relaxation of in-network charge alternation
appears to be significantly affected by the presence of separate polar
and apolar domains. However, we also find that if one was to assign
weight factors to the relaxation of the structural motifs, charge
alternation always contributes about the same amount (between 62.1
and 66.3%) across systems to the running integral of the stress tensor
correlation function from which the shear viscosity is derived. Adjacency
correlations between positive and negative moieties also contribute
an identical amount if a prepeak is not present (about 38%) and a
slightly smaller amount (about 28%) when intermediate range order
exists. The prepeak only contributes about 6% to viscoelastic relaxation,
highlighting that the dynamics of the smaller scale motifs is the
most important.
Collapse
Affiliation(s)
| | - Juan C Araque
- School of Engineering, Benedictine College, Atchison, Kansas 66002, United States
| | - Claudio J Margulis
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| |
Collapse
|
12
|
Philippi F, Welton T. Targeted modifications in ionic liquids - from understanding to design. Phys Chem Chem Phys 2021; 23:6993-7021. [PMID: 33876073 DOI: 10.1039/d1cp00216c] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ionic liquids are extremely versatile and continue to find new applications in academia as well as industry. This versatility is rooted in the manifold of possible ion types, ion combinations, and ion variations. However, to fully exploit this versatility, it is imperative to understand how the properties of ionic liquids arise from their constituents. In this work, we discuss targeted modifications as a powerful tool to provide understanding and to enable design. A 'targeted modification' is a deliberate change in the structure of an ionic liquid. This includes chemical changes in an experiment as well as changes to the parameterisation in a computer simulation. In any case, such a change must be purposeful to isolate what is of interest, studying, as far as is possible, only one concept at a time. The concepts can then be used as design elements. However, it is often found that several design elements interact with each other - sometimes synergistically, and other times antagonistically. Targeted modifications are a systematic way of navigating these overlaps. We hope this paper shows that understanding ionic liquids requires experimentalists and theoreticians to join forces and provides a tool to tackle the difficult transition from understanding to design.
Collapse
Affiliation(s)
- Frederik Philippi
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, London W12 0BZ, UK.
| | | |
Collapse
|
13
|
Di Pietro ME, Castiglione F, Mele A. Polar/apolar domains' dynamics in alkylimidazolium ionic liquids unveiled by the dual receiver NMR 1H and 19F relaxation experiment. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114567] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
14
|
Photophysics and rotational dynamics of Nile red in room temperature ionic liquid (RTIL) and RTIL-cosolvents binary mixtures. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2020.112550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
15
|
Di
Pietro ME, Castiglione F, Mele A. Anions as Dynamic Probes for Ionic Liquid Mixtures. J Phys Chem B 2020; 124:2879-2891. [PMID: 32186377 PMCID: PMC7997561 DOI: 10.1021/acs.jpcb.0c00026] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/14/2020] [Indexed: 11/28/2022]
Abstract
Ionic liquid (IL) mixtures have been proposed as a viable alternative to rationally fine-tune the physicochemical properties of ILs for a variety of applications. The understanding of the effects of mixing ILs on the properties of the mixtures is however only in the very early stages. Two series of ionic liquid mixtures, based on the 1-ethyl-3-methylimidazolium and 1-dodecyl-3-methylimidazolium cations, and having a common anion (tetrafluoroborate or bis(trifluoromethylsulfonyl)imide), have been prepared and deeply characterized via multiple NMR techniques. Diffusion and relaxation methods combined with 2D ion-ion correlation (nuclear Overhauser enhancement) experiments have been used for a better understanding of the interplay between dynamics and structure of IL mixtures. A crucial role of the anion in driving the mixture's behavior emerged, making them important "dynamic probes" for gaining information of the polar and nonpolar regions of ionic liquids and their mixtures.
Collapse
Affiliation(s)
- Maria Enrica Di
Pietro
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Franca Castiglione
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Andrea Mele
- Department
of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
- Istituto
di Scienze e Tecnologie Chimiche (SCITEC-CNR), Via A. Corti 12, 20133 Milano, Italy
| |
Collapse
|
16
|
Wang Y, Jarošová R, Swain GM, Blanchard GJ. Characterizing the Magnitude and Structure-Dependence of Free Charge Density Gradients in Room-Temperature Ionic Liquids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:3038-3045. [PMID: 32148037 DOI: 10.1021/acs.langmuir.0c00237] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We have reported previously on the existence of charge-induced long-range organization in the room-temperature ionic liquid (RTIL), BMIM+BF4-. The induced organization is in the form of a free charge density gradient (ρf) that exists over ca. 100 μm into the RTIL in contact with a charged surface. The fluorescence anisotropy decay of a trace-level charged chromophore in the RTIL is measured as a function of distance from the indium-doped tin oxide support surface to probe this free charge density gradient. We report here on the characterization of the free charge density gradient in five different imidazolium RTILs and use these data to evaluate the magnitude of the induced free charge density gradient. Both the extent and magnitude of this gradient depend on the chemical structures of the cationic and anionic constituents of the RTIL used. Control over the magnitude of ρf has implications for the utility of RTILs for a host of applications that remain to be explored fully.
Collapse
Affiliation(s)
- Yufeng Wang
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Romana Jarošová
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
- Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic
| | - Greg M Swain
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| | - Gary J Blanchard
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States
| |
Collapse
|
17
|
Bystrov SS, Matveev VV, Chernyshev YS, Balevičius V, Chizhik VI. Molecular Mobility in a Set of Imidazolium-Based Ionic Liquids [bmim]+A– by the NMR-Relaxation Method. J Phys Chem B 2019; 123:2362-2372. [DOI: 10.1021/acs.jpcb.8b11250] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergei S. Bystrov
- Saint Petersburg State University, University Embankment, 7/9, 199034 Saint-Petersburg, Russia
| | - Vladimir V. Matveev
- Saint Petersburg State University, University Embankment, 7/9, 199034 Saint-Petersburg, Russia
| | - Yurii S. Chernyshev
- Saint Petersburg State University, University Embankment, 7/9, 199034 Saint-Petersburg, Russia
| | | | - Vladimir I. Chizhik
- Saint Petersburg State University, University Embankment, 7/9, 199034 Saint-Petersburg, Russia
| |
Collapse
|
18
|
Kumar P, Prakash P, Ramya KR, Venkatnathan A. Probing translational and rotational dynamics in hydrophilic/hydrophobic anion based imidazolium ionic liquid-water mixtures. SOFT MATTER 2018; 14:6109-6118. [PMID: 29998279 DOI: 10.1039/c8sm00765a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this investigation, we examine the effect of water concentration and temperature on the dynamical properties of [Hmim][Cl] and [Hmim][NTf2] ionic liquids (ILs). The dynamical properties such as translational diffusion coefficients, ion-pair lifetimes, and rotational correlation times are calculated using molecular dynamics simulations. The simulations predict that water concentration also significantly impacts the magnitude of dynamical properties. At low, intermediate and high water concentrations, the following trend in diffusion coefficients is seen: Cl- > Hmim+; Cl- > NTf2-; Hmim+ ([Hmim][Cl]) > Hmim+ ([Hmim] [NTf2]). At ultra-low water concentrations of [Hmim][Cl] IL, several bridge like configurations form between water molecules and Cl- anions, which are supported by a complex distribution of water clusters. The effect of an increase in the water concentration leads to a decrease in ion-pair lifetimes between the Hmim+ cations and Cl-/NTf2- anions, which strongly correlates with the trends observed from the diffusion coefficients. A biexponential function was found to be the best fit for the RACF at neat/ultra-low water concentrations of [Hmim][Cl] and [Hmim][NTf2] ILs, whereas a single exponential function was sufficient to fit the RACF at low, intermediate and high water concentrations. The rotational relaxation time of the Hmim+ cations is larger in neat [Hmim][Cl] compared to that in neat [Hmim][NTf2] with an opposite trend seen with hydration. The rotational correlation time of water molecules is larger in [Hmim][Cl] compared to that in [Hmim][NTf2] at low and intermediate water concentrations, with similar correlation times observed at high water concentrations.
Collapse
Affiliation(s)
- Praveen Kumar
- Department of Chemistry and Centre for Energy Science, Indian Institute of Science Education and Research, Pune 411008, India.
| | | | | | | |
Collapse
|
19
|
Conway B, Uitvlugt C, Maroncelli M. Simulations of 1-Butyl-3-methylimidazolium Tetrafluoroborate + Acetonitrile Mixtures: Force-Field Validation and Frictional Characteristics. J Phys Chem B 2018; 122:7385-7393. [DOI: 10.1021/acs.jpcb.8b04341] [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)
- Brian Conway
- The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Caleb Uitvlugt
- The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mark Maroncelli
- The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|
20
|
Avula NVS, Mondal A, Balasubramanian S. Charge Environment and Hydrogen Bond Dynamics in Binary Ionic Liquid Mixtures: A Computational Study. J Phys Chem Lett 2018; 9:3511-3516. [PMID: 29883123 DOI: 10.1021/acs.jpclett.8b01481] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The extent of charge transfer between the cation and the anion in a room-temperature ionic liquid depends on the basicity of the anion. Ion charges determined in the condensed state via density functional theory calculations capture this effect rather well, and charges derived in such a manner have been employed in force field-based molecular dynamics simulations to quantitatively reproduce several physical properties of the liquids. However, the issue of transferability of cation charges in mixtures of ionic liquids, say with one type of cation and two different anion types needs to be addressed. Herein, we demonstrate that the cation charge in such a mixture varies linearly with anion composition, a result that ties in rather well with X-ray photoelectron spectroscopic experiments. The variation in cation charge with bulk anion composition is shown to be a result of changes in its coordination environment. Cations surrounded by a higher proportion of more basic anions possess lower charges than those surrounded by less basic anions. Time scales for the exchange of anion types for the occupation of hydrogen bonding sites around the cation have been determined and are seen to be constituted by three processes-breakage of existing hydrogen bond, diffusion to the hydrogen bonding site and displacement of the incumbent anion from its site in the cation coordination shell. These time scales explain the differences observed between infrared and NMR spectroscopic experiments in ionic liquid mixtures rather well.
Collapse
Affiliation(s)
- Nikhil V S Avula
- Chemistry and Physics of Materials Unit , Jawaharlal Nehru Centre for Advanced Scientific Research , Bangalore 560064 , India
| | - Anirban Mondal
- Chemistry and Physics of Materials Unit , Jawaharlal Nehru Centre for Advanced Scientific Research , Bangalore 560064 , India
| | - Sundaram Balasubramanian
- Chemistry and Physics of Materials Unit , Jawaharlal Nehru Centre for Advanced Scientific Research , Bangalore 560064 , India
| |
Collapse
|
21
|
Das S, Mukherjee B, Biswas R. Orientational dynamics in a room temperature ionic liquid: Are angular jumps predominant? J Chem Phys 2018; 148:193839. [DOI: 10.1063/1.5017797] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Suman Das
- Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India
| | - Biswaroop Mukherjee
- Thematic Unit for Excellence–Computational Materials Science, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India
| | - Ranjit Biswas
- Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India
- Thematic Unit for Excellence–Computational Materials Science, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700106, India
| |
Collapse
|
22
|
Strate A, Neumann J, Overbeck V, Bonsa AM, Michalik D, Paschek D, Ludwig R. Rotational and translational dynamics and their relation to hydrogen bond lifetimes in an ionic liquid by means of NMR relaxation time experiments and molecular dynamics simulation. J Chem Phys 2018; 148:193843. [DOI: 10.1063/1.5011804] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Anne Strate
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Dr.-Lorenz-Weg 2, D-18059 Rostock, Germany
| | - Jan Neumann
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Albert-Einstein-Straße 21, D-18059 Rostock, Germany
| | - Viviane Overbeck
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Dr.-Lorenz-Weg 2, D-18059 Rostock, Germany
| | - Anne-Marie Bonsa
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Dr.-Lorenz-Weg 2, D-18059 Rostock, Germany
| | - Dirk Michalik
- Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, D-18059 Rostock, Germany
| | - Dietmar Paschek
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Albert-Einstein-Straße 21, D-18059 Rostock, Germany
| | - Ralf Ludwig
- Institut für Chemie, Abteilung Physikalische und Theoretische Chemie, Universität Rostock, Dr.-Lorenz-Weg 2, D-18059 Rostock, Germany
- Leibniz Institut für Katalyse an der Universität Rostock, Albert-Einstein-Straße 29a, D-18059 Rostock, Germany
| |
Collapse
|
23
|
Ma R, Wang X, Jie J, Yan L, Kuang Z, Guo Q, Li B, Xia A. Probing Laser-Induced Heterogeneous Microenvironment Changes in Room-Temperature Ionic Liquids. Chemphyschem 2017; 18:2881-2889. [PMID: 28834094 DOI: 10.1002/cphc.201700772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 08/17/2017] [Indexed: 12/31/2022]
Abstract
Modulating the heterogeneous microenvironment in room-temperature ionic liquids (RTILs) by external stimuli is an important approach for understanding and designing external field-induced chemical reactions in natural and applied systems. Here, we report for the first time the redistribution of oxygen molecules related to microstructure changes in RTILs induced by an external laser field, which is probed simultaneously by the triplet-state dynamics of porphyrin. A remarkably long-lived triplet state of porphyrin is observed with changes of microstructures after irradiation, suggesting that charge-shifted O2 molecules are induced by the external field and/or rearranged intrinsic ions move from nonpolar domains into the polar domains of RTILs through electrostatic interactions. The results suggest that heterogeneous systems like ionic liquids in the presence of external stimuli can be designed for reaction systems associated with not only O2 but also for CO2 , CS2 , etc. and many other similar solvent molecules for many promising applications.
Collapse
Affiliation(s)
- Renjun Ma
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Xian Wang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Jialong Jie
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Linyin Yan
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.,Reed Elsevier Information Technology (Beijing) Co., Ltd., Beijing, 100738, People's Republic of China
| | - Zhuoran Kuang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Qianjin Guo
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Boxuan Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| | - Andong Xia
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, 100190, People's Republic of China
| |
Collapse
|
24
|
Wu B, Maroncelli M, Castner EW. Photoinduced Bimolecular Electron Transfer in Ionic Liquids. J Am Chem Soc 2017; 139:14568-14585. [DOI: 10.1021/jacs.7b07611] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Boning Wu
- Department of Chemistry
and Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854, United States
| | - Mark Maroncelli
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Edward W. Castner
- Department of Chemistry
and Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854, United States
| |
Collapse
|
25
|
Rumble CA, Uitvlugt C, Conway B, Maroncelli M. Solute Rotation in Ionic Liquids: Size, Shape, and Electrostatic Effects. J Phys Chem B 2017; 121:5094-5109. [DOI: 10.1021/acs.jpcb.7b01704] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher A. Rumble
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Caleb Uitvlugt
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Brian Conway
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mark Maroncelli
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|