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Souna AJ, Cohen SR, Rivera CA, Manfred K, Coasne B, Fourkas. JT. The Role of Resonant Coupling in Vibrational Sum-Frequency-Generation Spectroscopy: Liquid Acetonitrile at the Silica Interface. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Johnson CA, Parker AW, Donaldson PM, Garrett-Roe S. An ultrafast vibrational study of dynamical heterogeneity in the protic ionic liquid ethyl-ammonium nitrate. I. Room temperature dynamics. J Chem Phys 2021; 154:134502. [PMID: 33832238 DOI: 10.1063/5.0044822] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Using ultrafast two-dimensional infrared spectroscopy (2D-IR), a vibrational probe (thiocyanate, SCN-) was used to investigate the hydrogen bonding network of the protic ionic liquid ethyl-ammonium nitrate (EAN) in comparison to H2O. The 2D-IR experiments were performed in both parallel (⟨ZZZZ⟩) and perpendicular (⟨ZZXX⟩) polarizations at room temperature. In EAN, the non-Gaussian lineshape in the FTIR spectrum of SCN- suggests two sub-ensembles. Vibrational relaxation rates extracted from the 2D-IR spectra provide evidence of the dynamical differences between the two sub-ensembles. We support the interpretation of two sub-ensembles with response function simulations of two overlapping bands with different vibrational relaxation rates and, otherwise, similar dynamics. The measured rates for spectral diffusion depend on polarization, indicating reorientation-induced spectral diffusion (RISD). A model of restricted molecular rotation (wobbling in a cone) fully describes the observed spectral diffusion in EAN. In H2O, both RISD and structural spectral diffusion contribute with similar timescales. This complete characterization of the dynamics at room temperature provides the basis for the temperature-dependent measurements in Paper II of this series.
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Affiliation(s)
- Clinton A Johnson
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, USA
| | - Anthony W Parker
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Harwell Campus, Didcot, United Kingdom
| | - Paul M Donaldson
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Harwell Campus, Didcot, United Kingdom
| | - Sean Garrett-Roe
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, USA
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Ren Z, Kelly J, Gunathilaka CP, Brinzer T, Dutta S, Johnson CA, Mitra S, Garrett-Roe S. Ultrafast dynamics of ionic liquids in colloidal dispersion. Phys Chem Chem Phys 2017; 19:32526-32535. [PMID: 29188825 DOI: 10.1039/c7cp04441k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ionic liquid (IL)-surfactant complexes have significance both in applications and fundamental research, but their underlying dynamics are not well understood. We apply polarization-controlled two-dimensional infrared spectroscopy (2D-IR) to study the dynamics of [BMIM][SCN]/surfactant/solvent model systems. We examine the effect of the choice of surfactants and solvent, and the IL-to-surfactant ratio (W-value), with a detailed analysis of the orientation and structural dynamics of each system. Different surfactants create very different environments for the entrapped ILs, ranging from a semi-static micro-environment to a fluxional environment that evolves even faster than the bulk IL. The oil-phase also clearly affects the microscopic dynamics. The anisotropy decay for entrapped ILs completes within 10 ps, which is similar to free thiocyanate ion in water, while a significant reorientation-induced spectral diffusion (RISD) effect is observed. The entrapped ionic liquid are highly dynamic for all W-values, and no core-shell structure is observed. We hypothesize that, instead of an ionic liquid-reverse micelle (IL-RM), the microscopic structure of this system is small colloidal dispersions or pairs of IL and surfactants. A detailed analysis of the polarization-controlled 2D-IR spectra of AOT system reveals a potential ion-exchange mechanism.
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Affiliation(s)
- Zhe Ren
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, USA.
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Affiliation(s)
- Sean Garrett-Roe
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, USA
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Souna AJ, Bender JS, Fourkas JT. How clean is the solvent you use to clean your optics? A vibrational sum-frequency-generation study. Appl Opt 2017; 56:3875-3878. [PMID: 28463281 DOI: 10.1364/ao.56.003875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Solvents for cleaning optics often come into contact with plastic and/or rubber during storage and transfer. To explore the effects that exposure to these materials can have on solvents, we used vibrational sum-frequency-generation spectroscopy to study a silica optic following cleaning with solvents that had come into contact with either low-density polyethylene, high-density polyethylene, or rubber. Our studies show that even brief contact of acetone, methanol, or isopropanol with plastic or rubber can cause otherwise pure solvents to leave a persistent residue.
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Donovan MA, Yimer YY, Pfaendtner J, Backus EHG, Bonn M, Weidner T. Ultrafast Reorientational Dynamics of Leucine at the Air–Water Interface. J Am Chem Soc 2016; 138:5226-9. [DOI: 10.1021/jacs.6b01878] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Michael A. Donovan
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Yeneneh Y. Yimer
- Department
of Chemical Engineering, University of Washington, 105 Benson Hall, Seattle, Washington 98195-1750, United States
| | - Jim Pfaendtner
- Department
of Chemical Engineering, University of Washington, 105 Benson Hall, Seattle, Washington 98195-1750, United States
| | - Ellen H. G. Backus
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Tobias Weidner
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Kramer PL, Nishida J, Fayer MD. Separation of experimental 2D IR frequency-frequency correlation functions into structural and reorientation-induced contributions. J Chem Phys 2015; 143:124505. [DOI: 10.1063/1.4931402] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Patrick L. Kramer
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Jun Nishida
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Michael D. Fayer
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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Kramer PL, Nishida J, Giammanco CH, Tamimi A, Fayer MD. Observation and theory of reorientation-induced spectral diffusion in polarization-selective 2D IR spectroscopy. J Chem Phys 2015; 142:184505. [DOI: 10.1063/1.4920949] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Patrick L. Kramer
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Jun Nishida
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Chiara H. Giammanco
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Amr Tamimi
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - Michael D. Fayer
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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Affiliation(s)
- Shule Liu
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - John T. Fourkas
- Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
- Institute
for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, United States
- Maryland
NanoCenter, University of Maryland, College Park, Maryland 20742, United States
- Center
for Nanophysics and Advanced Materials, University of Maryland, College
Park, Maryland 20742, United States
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