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Title: Structure of cyano-anion ionic liquids: X-ray scattering and simulations

 [1]; ORCiD logo [2]; ORCiD logo [3];  [3];  [2];  [1];  [3]
  1. Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA
  2. Laboratório de Espectroscopia Molecular, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05513-970 São Paulo, SP, Brazil
  3. Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
Publication Date:
Sponsoring Org.:
OSTI Identifier:
Grant/Contract Number:
SC0001780; SC0008644
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 145; Journal Issue: 2; Related Information: CHORUS Timestamp: 2018-02-15 02:00:03; Journal ID: ISSN 0021-9606
American Institute of Physics
Country of Publication:
United States

Citation Formats

Dhungana, Kamal B., Faria, Luiz F. O., Wu, Boning, Liang, Min, Ribeiro, Mauro C. C., Margulis, Claudio J., and Castner, Jr., Edward W.. Structure of cyano-anion ionic liquids: X-ray scattering and simulations. United States: N. p., 2016. Web. doi:10.1063/1.4955186.
Dhungana, Kamal B., Faria, Luiz F. O., Wu, Boning, Liang, Min, Ribeiro, Mauro C. C., Margulis, Claudio J., & Castner, Jr., Edward W.. Structure of cyano-anion ionic liquids: X-ray scattering and simulations. United States. doi:10.1063/1.4955186.
Dhungana, Kamal B., Faria, Luiz F. O., Wu, Boning, Liang, Min, Ribeiro, Mauro C. C., Margulis, Claudio J., and Castner, Jr., Edward W.. 2016. "Structure of cyano-anion ionic liquids: X-ray scattering and simulations". United States. doi:10.1063/1.4955186.
title = {Structure of cyano-anion ionic liquids: X-ray scattering and simulations},
author = {Dhungana, Kamal B. and Faria, Luiz F. O. and Wu, Boning and Liang, Min and Ribeiro, Mauro C. C. and Margulis, Claudio J. and Castner, Jr., Edward W.},
abstractNote = {},
doi = {10.1063/1.4955186},
journal = {Journal of Chemical Physics},
number = 2,
volume = 145,
place = {United States},
year = 2016,
month = 7

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4955186

Citation Metrics:
Cited by: 15works
Citation information provided by
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  • Ionic liquids with cyano anions have long been used because of their unique combination of low-melting temperatures, reduced viscosities, and increased conductivities. Recently we have shown that cyano anions in ionic liquids are particularly interesting for their potential use as electron donors to excited state photo-acceptors [B. Wu et al., J. Phys. Chem. B 119, 14790–14799 (2015)]. Here we report on bulk structural and quantum mechanical results for a series of ionic liquids based on the 1-ethyl-3-methylimidazolium cation, paired with the following five cyano anions: SeCN-, SCN-, N(CN)-2N(CN)2-, C(CN)-3C(CN)3-, and B(CN)-4B(CN)4-. By combining molecular dynamics simulations, high-energy X-ray scattering measurements,more » and periodic boundary condition DFT calculations, we are able to obtain a comprehensive description of the liquid landscape as well as the nature of the HOMO-LUMO states for these ionic liquids in the condensed phase. Features in the structure functions for these ionic liquids are somewhat different than the commonly observed adjacency, charge-charge, and polarity peaks, especially for the bulkiest B(CN)-4B(CN)4- anion. While the other four cyano-anion ionic liquids present an anionic HOMO, the one for Im+2,1Im2,1+/B(CN)-4B(CN)4- is cationic.« less
  • A combination of X-ray scattering experiments and molecular dynamics simulations were conducted to investigate the structure of ionic liquids (ILs) which chemically bind CO 2. The structure functions were measured and computed for four different ILs consisting of two different phosphonium cations, triethyloctylphosphonium ([P 2228] +) and trihexyltetradecylphosphonium ([P 66614] +), paired with two different aprotic heterocyclic anions which chemically react with CO 2, 2-cyanopyrrolide, and 1,2,4-triazolide. Simulations were able to reproduce the experimental structure functions, and by deconstructing the simulated structure functions, further information on the liquid structure was obtained. All structure functions of the ILs studied had threemore » primary features which have been seen before in other ILs: a prepeak near 0.3–0.4 Å–1 corresponding to polar/nonpolar domain alternation, a charge alternation peak near 0.8 Å–1, and a peak near 1.5 Å–1 due to interactions of adjacent molecules. The liquid structure functions were only mildly sensitive to the specific anion and whether or not they were reacted with CO 2. Upon reacting with CO 2, small changes were observed in the structure functions of the [P 2228] + ILs, whereas virtually no change was observed upon reacting with CO 2 in the corresponding [P 66614] + ILs. When the [P 2228] + cation was replaced with the [P 66614] + cation, there was a significant increase in the intensities of the prepeak and adjacency interaction peak. While many of the liquid structure functions are similar, the actual liquid structures differ as demonstrated by computed spatial distribution functions.« less
  • In this article we determine the temperature-dependent structure of the tetradecyltrihexylphosphonium bis(trifluoromethylsulfonyl)amide ionic liquid using a combination of X-ray scattering and molecular dynamics simulations. As in many other room-temperature ionic liquids three characteristic intermolecular peaks can be detected in the structure function S(q). A prepeak or first sharp diffraction peak is observed at about q = 0.42 {angstrom}{sup -1}. Long range anion-anion correlations are the most important contributors to this peak. In all systems we have studied to date, this prepeak is a signature of solvation asymmetry. The peak in S(q) near q = 0.75 {angstrom}{sup -1} is the signaturemore » of ionic alternation and arises from the charge ordered separation of ions of the same charge. The most intense diffraction peak near q = 1.37 {angstrom}{sup -1} arises from short-range separation between ions of opposite charge combined with a significant contribution from cationic carbon-carbon interactions, indicating that cationic hydrophobic tails have significant contacts.« less
  • Activity coefficients of 52 organic compounds in four ionic liquids (ILs), 1,3-dimethoxyimidazolium bis((trifluoromethyl)sulfonyl)imide, 1-(methylethylether)-3-methylimidazolium bis((trifluoromethyl)sulfonyl) imide, 1-ethanol-3-methylimidazolium bis((trifluoromethyl)-sulfonyl)imide, and 1-(3-cyanopropyl)-3- methylimidazolium dicyanamide, were measured using inverse gas chromatography from (312 to 353) K. The retention data were also converted in gas-to-IL partition coefficients and water-to-IL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analyzed using the modified Abraham solvation parameter model. The derived equations correlated the experimental gas-to-IL and water-to-IL partition coefficient data to within (0.09 and 0.14) log units, respectively.
  • Cited by 5