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Kimura Y, Akai R, Shimada K, Hirata M, Fujii K, Endo T. Anomalous Dependence of Translational Diffusion on the Water Mole Fraction for Solute Molecules Dissolved in a 1-Butyl-3-methylimidazolium Tetrafluoroborate/Water Mixture. J Phys Chem B 2023. [PMID: 37310854 DOI: 10.1021/acs.jpcb.3c01978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Translational diffusion coefficients of carbon monoxide (CO), diphenylacetylene (DPA), and diphenylcyclopropenone (DPCP) were determined in mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim]BF4) and water using transient grating spectroscopy at different mole fractions of water (xw). While DPA exhibited a larger diffusion coefficient than DPCP at low water mole fractions (xw < 0.7), as observed for conventional liquids and ionic liquids (ILs), it was smaller at high mole fractions (xw > 0.9). The apparent molecular radius of DPA determined using the Stokes-Einstein equation at xw > 0.9 is close to the radius of an IL cluster in a water pool as determined from small-angle neutron scattering experiments (J. Bowers et al., Langmuir, 2004, 20, 2192-2198), suggesting that the DPA molecules are trapped in IL clusters in the water pool and move together. The solvation state of DPCP in the mixture was studied using Raman spectroscopy. Dramatically strong water/DPCP hydrogen bonding was observed at higher water mole fractions, suggesting that DPCP is located near the cluster interfaces. The large diffusion coefficient of DPCP suggests that hopping of DPCP between IL clusters occurs through hydrogen bonding with water.
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Affiliation(s)
- Yoshifumi Kimura
- Division of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, 2-1, Tatara Miyakodani, Kyotanabe 610-0321, Kyoto, Japan
- Department of Applied Chemistry, Graduate School of Science and Engineering, Doshisha University, 2-1, Tatara Miyakodani, Kyotanabe-City 610-0321, Kyoto, Japan
| | - Rie Akai
- Division of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, 2-1, Tatara Miyakodani, Kyotanabe 610-0321, Kyoto, Japan
| | - Kohei Shimada
- Department of Applied Chemistry, Graduate School of Science and Engineering, Doshisha University, 2-1, Tatara Miyakodani, Kyotanabe-City 610-0321, Kyoto, Japan
| | - Mizuki Hirata
- Division of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, 2-1, Tatara Miyakodani, Kyotanabe 610-0321, Kyoto, Japan
| | - Kaori Fujii
- Division of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, 2-1, Tatara Miyakodani, Kyotanabe 610-0321, Kyoto, Japan
| | - Takatsugu Endo
- Division of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, 2-1, Tatara Miyakodani, Kyotanabe 610-0321, Kyoto, Japan
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Kimura Y, Ibaraki S, Hirano R, Sugita Y, Yasaka Y, Ueno M. Photoexcitation dynamics of p-nitroaniline and N,N-dimethyl-p-nitroaniline in 1-alkyl-3-methylimidazolium-cation based ionic liquids with different alkyl-chain lengths. Phys Chem Chem Phys 2017; 19:22161-22168. [DOI: 10.1039/c7cp03610h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Back electron transfer and vibrational energy relaxation of p-nitroaniline and N,N-dimethyl-p-nitroaniline in ionic liquids were investigated using transient absorption spectroscopy.
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Affiliation(s)
- Y. Kimura
- Department of Molecular Chemistry and Biochemistry
- Faculty of Science and Engineering
- Doshisha University
- Kyotanabe
- Japan
| | - S. Ibaraki
- Department of Molecular Chemistry and Biochemistry
- Faculty of Science and Engineering
- Doshisha University
- Kyotanabe
- Japan
| | - R. Hirano
- Department of Molecular Chemistry and Biochemistry
- Faculty of Science and Engineering
- Doshisha University
- Kyotanabe
- Japan
| | - Y. Sugita
- Department of Molecular Chemistry and Biochemistry
- Faculty of Science and Engineering
- Doshisha University
- Kyotanabe
- Japan
| | - Y. Yasaka
- Department of Molecular Chemistry and Biochemistry
- Faculty of Science and Engineering
- Doshisha University
- Kyotanabe
- Japan
| | - M. Ueno
- Department of Molecular Chemistry and Biochemistry
- Faculty of Science and Engineering
- Doshisha University
- Kyotanabe
- Japan
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