1
|
Leier J, Michenfelder NC, Unterreiner A. Understanding the Photoexcitation of Room Temperature Ionic Liquids. ChemistryOpen 2021; 10:72-82. [PMID: 33565733 PMCID: PMC7874249 DOI: 10.1002/open.202000278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/26/2020] [Indexed: 12/14/2022] Open
Abstract
Photoexcitation of (neat) room temperature ionic liquids (RTILs) leads to the observation of transient species that are reminiscent of the composition of the RTILs themselves. In this minireview, we summarize state-of-the-art in the understanding of the underlying elementary processes. By varying the anion or cation, one aim is to generally predict radiation-induced chemistry and physics of RTILs. One major task is to address the fate of excess electrons (and holes) after photoexcitation, which implies an overview of various formation mechanisms considering structural and dynamical aspects. Therefore, transient studies on time scales from femtoseconds to microseconds can greatly help to elucidate the most relevant steps after photoexcitation. Sometimes, radiation may eventually result in destruction of the RTILs making photostability another important issue to be discussed. Finally, characteristic heterogeneities can be associated with specific physicochemical properties. Influencing these properties by adding conventional solvents, like water, can open a wide field of application, which is briefly summarized.
Collapse
Affiliation(s)
- Julia Leier
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 276131KarlsruheGermany
| | - Nadine C. Michenfelder
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 276131KarlsruheGermany
| | - Andreas‐Neil Unterreiner
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 276131KarlsruheGermany
| |
Collapse
|
2
|
Knudtzon MN, Blank DA. Photodetachment and Electron Dynamics in 1-Butyl-1-methyl-pyrrolidinium Dicyanamide. J Phys Chem B 2020; 124:9144-9153. [PMID: 32955885 DOI: 10.1021/acs.jpcb.0c06508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ultrafast transient absorption spectrum of 1-butyl-1-methyl-pyrrolidinium dicyanamide, [Pyr1,4+][DCA-], was measured in the visible and near-infrared (IR) spectral regions. Excitation of the liquid at 4.6 eV created initially delocalized and highly reactive electrons that either geminately recombined (69%) or localized onto a cavity with a time constant of ∼300 fs. Electron localization was reflected in the evolution of the TA spectrum and the time-dependent loss of reactivity with a dichloromethane quencher. The delocalized initial state and spectrum of the free electrons were consistent with computational predictions by Xu and Margulis [ J. Phys. Chem. B, 2015, 119, 532-542] on excess electrons in [Pyr1,4+][DCA-]. The computational study considered two possible localization mechanisms for excess electrons, localization on ions, and localization on cavities. In the case of photogenerated electron-hole pairs, the results presented here demonstrate localization to cavities as the dominant channel. Following localization onto a cavity, the free electrons underwent solvation and loss of reactivity with the quencher with rates that slowed in time. The dynamics were similar to an analogous prior study on the related liquid [Pyr1,x+][NTf2-]. One significant difference was the larger yield of free electrons from photoexcitation of [Pyr1,4+][DCA-]. This was found to primarily reflect more efficient localization onto cavities rather than a slower geminate recombination rate.
Collapse
Affiliation(s)
- Meghan N Knudtzon
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - David A Blank
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
3
|
Ye M, Iwata K. Ultrafast Electron Solvation in Room Temperature Ionic Liquid Observed by Femtosecond Time-resolved Near-IR Spectroscopy. CHEM LETT 2019. [DOI: 10.1246/cl.181043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Manping Ye
- College of Optical and Electronic Technology, China Jiliang University, Hangzhou 310018, P. R. China
- Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Koichi Iwata
- Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| |
Collapse
|
4
|
Wu F, Xu C, Margulis CJ. Dynamics of an excess hole in the 1-methyl-1-butyl-pyrrolidinium dicyanamide ionic-liquid. J Chem Phys 2018; 148:193831. [DOI: 10.1063/1.5009940] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Fei Wu
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA
| | - Changhui Xu
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA
| | | |
Collapse
|
5
|
Das L, Kumar R, Maity DK, Adhikari S, Dhiman SB, Wishart JF. Pulse Radiolysis and Computational Studies on a Pyrrolidinium Dicyanamide Ionic Liquid: Detection of the Dimer Radical Anion. J Phys Chem A 2018; 122:3148-3155. [PMID: 29510054 DOI: 10.1021/acs.jpca.8b00978] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A pulse radiolysis study on pyrrolidinium cation based ionic liquids is presented herein. Time-resolved absorption spectra for 1-methyl-1-propylpyrrolidinium dicyanamide (DCA) at 500 ns after the electron pulse show broad absorption bands at wavelengths below 440 nm and at 640 nm. In pyrrolidinium bis(trifluoromethylsulfonyl)imide (NTf2) and tris(perfluoroethyl)trifluorophosphate (FAP) ILs, the transient absorption below 440 nm is much weaker. The absorption at 500 ns, which increases with wavelength from 500 nm to beyond 800 nm, was assigned to the tail of the solvated electron NIR absorption spectrum, since it disappears in the presence of N2O. In the DCA IL, the presence of a reducing species was confirmed by the formation of pyrene radical anion. The difference in the transient species in the case of the DCA IL compared to other two ILs should be due to the anion, with cations being similar. In pseudohalide ILs such as DCA, radicals are formed by direct hole trapping by the anion (X- + h+ → X•), followed by addition to the parent anion. Prediction of the UV/vis absorption spectra of the dimer radical anion by computational calculation supports the experimental results. The oxidizing efficiency of (DCA)2•- and its reduction potential ( E(DCA)2•-/(2DCA-)) have been determined.
Collapse
Affiliation(s)
- Laboni Das
- Radiation & Photochemistry Division , Bhabha Atomic Research Centre , Mumbai 400085 , India.,Homi Bhabha National Institute , Anushaktinagar, Mumbai 400094 , India
| | - Rahul Kumar
- Homi Bhabha National Institute , Anushaktinagar, Mumbai 400094 , India
| | - Dilip K Maity
- Homi Bhabha National Institute , Anushaktinagar, Mumbai 400094 , India
| | - Soumyakanti Adhikari
- Radiation & Photochemistry Division , Bhabha Atomic Research Centre , Mumbai 400085 , India
| | - Surajdevprakash B Dhiman
- Chemistry Division , Brookhaven National Laboratory , Upton , New York 11973-5000 , United States
| | - James F Wishart
- Chemistry Division , Brookhaven National Laboratory , Upton , New York 11973-5000 , United States
| |
Collapse
|
6
|
Saenko EV, Lukianova MA, Shiryaeva ES, Takahashi K, Feldman VI. Radiation-induced intermediates in irradiated glassy ionic liquids at low temperature. Radiat Phys Chem Oxf Engl 1993 2016. [DOI: 10.1016/j.radphyschem.2015.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
7
|
Musat RM, Kondoh T, Gohdo M, Yoshida Y, Takahashi K. Radiolytic yields of solvated electrons in ionic liquid and its solvation dynamics at low temperature. Radiat Phys Chem Oxf Engl 1993 2016. [DOI: 10.1016/j.radphyschem.2015.11.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
8
|
Molins i Domenech F, Healy AT, Blank DA. Photodetachment, electron cooling, and recombination, in a series of neat aliphatic room temperature ionic liquids. J Chem Phys 2015; 143:064506. [DOI: 10.1063/1.4927915] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Andrew T. Healy
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - David A. Blank
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA
| |
Collapse
|
9
|
Xu C, Margulis CJ. Solvation of an Excess Electron in Pyrrolidinium Dicyanamide Based Ionic Liquids. J Phys Chem B 2015; 119:532-42. [DOI: 10.1021/jp5108922] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Changhui Xu
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Claudio J. Margulis
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| |
Collapse
|
10
|
Shkrob IA, Marin TW, Wishart JF, Grills DC. Radiation Stability of Cations in Ionic Liquids. 5. Task-Specific Ionic Liquids Consisting of Biocompatible Cations and the Puzzle of Radiation Hypersensitivity. J Phys Chem B 2014; 118:10477-92. [DOI: 10.1021/jp5049716] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ilya A. Shkrob
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Timothy W. Marin
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
- Chemistry
Department, Benedictine University, 5700 College Road, Lisle, Illinois 60532, United States
| | - James F. Wishart
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - David C. Grills
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| |
Collapse
|
11
|
Musat RM, Kondoh T, Yoshida Y, Takahashi K. Twin-peaks absorption spectra of excess electron in ionic liquids. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2014.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
12
|
Xu C, Durumeric A, Kashyap HK, Kohanoff J, Margulis CJ. Dynamics of Excess Electronic Charge in Aliphatic Ionic Liquids Containing the Bis(trifluoromethylsulfonyl)amide Anion. J Am Chem Soc 2013; 135:17528-36. [DOI: 10.1021/ja409338z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Changhui Xu
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52241, United States
| | - Aleksander Durumeric
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52241, United States
| | - Hemant K. Kashyap
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52241, United States
| | - Jorge Kohanoff
- Atomistic
Simulation Centre, Queen’s University Belfast, BT7 1NN, United Kingdom
| | - Claudio J. Margulis
- Department
of Chemistry, University of Iowa, Iowa City, Iowa 52241, United States
| |
Collapse
|