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Faculty Research

Castner, Jr., Edward W.


Research Synopsis: Physical chemistry and chemical physics of ionic liquids

Phone: (848) 445-2564







Research Summary

The focus of our the research efforts in our group involves ionic liquids, or molten salts that are liquid at room temperature.  We study the physical and chemical behaviors of these novel liquids using a combination of methods, including time-resolved laser spectroscopy, synchrotron-based x-ray scattering and multi-dimensional NMR experiments.  We will on occasion synthesize a novel ionic liquid that is expected to display unique properties.  We enjoy participating in a wide range of collaborations, including those with the Blank, Margulis, Maronceli and Wishart groups.

Current Projects

Structure, Dynamics and Interactions in Novel Room-Temperature Ionic Liquids

  • High-energy X-ray scattering and molecular dynamics
  • Anomalous transport in ionic liquids probed by NMR
  • Creation of novel ionic liquids with silicon-substituted cations
  • Comparative studies of ionic liquids and their homologous neutral binary solution analogs
  • OHD-RIKES as a probe of intermolecular dynamics and orientational relaxation

Photo-induced Electron-Transfer in Ionic Liquids

  • Bimolecular photo-induced electron-transfer reactions in ionic liquid solvents


  • We wish to acknowledge support for our research from the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Bioscience under SISGR Grant no DE-FG02-09ER16118 and from the U.S. National Science Foundation, Directorate for Mathematical and Physical Sciences, Divison of Chemistry under grant CHE-1362272.


A. B. Biedron, E. L. Garfunkel, E. W. Castner, Jr., and S. Rangan, "Ionic Liquid Ultrathin Films at the Surface of Cu(100) and Au(111), J. Chem. Phys., A16.09.0104, submitted.

B. Wu, Y. Yamashita, T. Endo, K. Takahashi, and E. W. Castner, Jr., "Structure and Dynamics of Ionic Liquids:  Trimethylsilylpropyl-Substituted Cations and Bis(sulfonyl)amide Anions", J. Chem. Phys., 145, 244506 (2016), doi: 10.1063/1.4972410.

J. J. Hettige, W. D. Amith, E. W. Castner, Jr. and C. J. Margulis, "Ionic Liquids with Symmetric Isoelectronic Diether Tails:  Bulk and Vacuum-Liquid Interfacial Structures", J. Phys. Chem. B 2016doi: 10.1021/acs.jpcb.6b09148.

Q. Sheridan, S. Oh, O. Morales-Collazo, E. W. Castner, Jr., J. F. Brennecke and E. J. Maginn, "Liquid Structure of CO2-Reactive Aprotic Heterocyclic Anion Ionic Liquids from X-ray Scattinerg and Molecular Dynamics, J. Phys. Chem. B 2016120, 11951-11960. doi: 10.1021/acs.jpcb.6b07713.

W. D. Amith, J. J. Hettige, E. W. Castner, Jr., and C. J. Margulis, "Structures of Ionic Liquids Having both Anionic and Cationic Octyl Tails:  Lamellar Vacuum Interface vs. Sponge-Like Bulk Order", J. Phys. Chem. Lett. 2016, 7, 3785–3790.  doi:  10.1021/acs.jpclett.6b01763.

B. Wu, H. Shirota, S. Lall-Ramnarine and E. W. Castner, Jr., "Structure of Ionic Liquids with Cationic Silicon-Substitutions", J. Chem. Phys. 145, 114501 (2016).  doi:  10.1063/1.4962257.

K. B. Dhungana, L. F. O. Faria, B. Wu, M. Liang, M. C. C. Ribeiro, C. J. Margulis, and E. W. Castner, Jr., "Structure of cyano-anion ionic liquids:  X-ray scattering and simulations", J. Chem. Phys. 145, 024503 (2016).  doi:  10.1063/1.4955186.

B. Wu, M. Liang, M. Maroncelli, and E. W. Castner, Jr., "Photo-Induced Bimolecular Electron Transfer from Cyano-Anions in Ionic Liquids", J. Phys. Chem. B 2015, 119, 14790-14799.  doi: 10.1021/acs.jpcb.5b09216.

T. A. Fadeeva, P. Husson, J. A. DeVine, M. F. Costa Gomes, S. G. Greenbaum and E. W. Castner, Jr., "Interactions between water and 1-butyl-1-methylpyrrolidinium ionic liquids", J. Chem. Phys. 143, 064503 (2015).  doi:  10.1063/1.4928065.

J. A. DeVine, M. Labib, M. E. Harries, R. A. M. Rached, J. Issa, J. F. Wishart and E. W. Castner, Jr., "Electron Transfer Dynamics for a Donor-Bridge-Acceptor Complex in Ionic Liquids", J. Phys. Chem. B 2015, 119, 11336-11346.  doi: 10.1021/acs.jpcb.5b03320.

M. Liang, S. Khatun and E. W. Castner, Jr., "Communication: Unusual Structure and Transport in Ionic Liquid-Hexane Mixtures", J. Chem. Phys. 142, 121101 (2015).  doi: 10.1063/1.4916388.

S. Khatun and E. W. Castner, Jr., "Ionic Liquid-Solute Interactions Studies by 2D NOE NMR Spectroscopy", J. Phys. Chem. B, 2015, 119, 9225-9235.  doi: 10.1021/jp509861g.

H. K. Kashyap, C. S. Santos, N. S. Murthy, J. J. Hettige, K. Kerr, S. Ramati, J. Gwon, M. Gohdo, S. I. Lall-Ramnarine, J. F. Wishart, C. J. Margulis, and E. W. Castner, Jr., "Structure of 1-Alkyl-1-methylpyrrolidinium Bis(trifluoromethylsulfonyl)amide Ionic Liquids with Linear, Branched and Cyclic Alkyl Groups", J. Phys. Chem. B, 2013, 117, 15328-15337.  doi:  10.1021/jp403518j.

H. Y. Lee, H. Shirota and E. W. Castner, Jr., "Differences in Ion Interactions for Isoelectronic Ionic Liquid Homologs", J. Phys. Chem. Lett. 2013, 4, 1477-1483.  doi:  10.1021/jz400465x.

H. K. Kashyap, C. S. Santos, R. P. Daly, J. J. Hettige, N. S. Murthy, H. Shirota, Edward W. Castner, Jr. and C. J. Margulis, "How Does the Ionic Liquid Organizational Landscape Change when Nonpolar Cationic Alkyl Groups Are Replaced by Polar Isoelectronic Diethers?", J. Phys. Chem. B, 2013, 117, 1130-1135.  doi:  10.1021/jp311032p

A. Triolo, O. Russina, R. Caminiti, H. Shirota, H. Y. Lee, C. S. Santos, N. S. Murthy, and E. W. Castner, Jr., "Comparing intermediate range order for alkyl- vs. ether-substituted cations in ionic liquids", Chem. Commun., 2012,48, 4103-4105.  doi:  10.1039/c2cc31550e.

H. Y. Lee, J. B. Issa, S. S. Isied, E. W. Castner, Jr., Y. Pan, C. L. Hussey, K. S. Lee and J. F. Wishart, "A Comparison of Electron-Transfer Dynamics in Ionic Liquids and Neutral Solvents", J. Phys. Chem. C 2012, 116, 5197-5208.  doi:  10.1021/jp208852r.

H. K. Kashyap, C. S. Santos, H. V. R. Annapureddy, N. S. Murthy, C. J. Margulis and Edward W. Castner, Jr., "Temperature-dependent structure of ionic liquids : X-ray scattering and simulations", Faraday Disc. 2012, 154, 133-143. doi: 10.1039/C1FD00059D.

C. S. Santos, N. S. Murthy, G. A. Baker, E. W. Castner, Jr., "X-ray scattering from ionic liquids with pyrrollidinium cations", J. Chem. Phys., 134, 121101 (2011).  doi: 10.1063/1.3569131.

E. W. Castner, Jr., C. J. Margulis, M. Maroncelli, and J. F. Wishart, "Ionic Liquids:  Structure and Photochemical Reactivity", Annu. Rev. Phys. Chem. 2011, 62, 85-105.  doi: 10.1146/annurev-physchem-032210-103421.

C. S. Santos, H. V. R. Annapureddy, N. S. Murthy, H. K. Kashyap, E. W. Castner, Jr. and C. J. Margulis, "Temperature-dependent structure of methyltributylammonium bis(trifluoromethylsulfonyl)amide:  x-ray scattering and simulations", J. Chem. Phys., 134, 064501 (2011).  doi:  10.1063/1.3526958

E. W. Castner, Jr. and J. F. Wishart, "Spotlight on ionic liquids", J. Chem. Phys. 132, 120901 (2010). doi: 10.1063/1.3373178

B. M. Krieger, H. Y. Lee, T. J. Emge, J. F. Wishart and E. W. Castner, Jr., "Ionic Liquids and Solids with Paramagnetic Anions", Phys. Chem. Chem. Phys., 2010, doi:10.1039/b920652n.

E. W. Castner, Jr., J. F. Wishart, and H. Shirota, "Intermolecular Dynamics, Interactions and Solvation in Ionic Liquids", Accounts of Chemical Research, 2007, 40(11), 1217-1227. doi: 10.1021/ar700169g

B. J. Lee, M. Barch, E. W. Castner, Jr., J. Völker, and K. J. Breslauer, "Structure and Dynamics in DNA looped Domains: CAG Triplet Repeat Sequence Dynamics Probed by 2-Aminopurine Fluorescence", Biochemistry, 2007, 46, 10756-10766. doi: 10.1021/bi7005674

J. F. Wishart and E. W. Castner, Jr., Editorial, "The Physical Chemistry of Ionic Liquids", J. Phys. Chem. B, 2007, 111(18), 4639-4640. doi: 10.1021/jp072262u. This editorial for the May 10, 2007 special issue of JPC B on the "Physical Chemistry of Ionic Liquids" was no. 14 on the Most-Accessed list for 2007.

S. H. Chung, R. Lopato, S. G. Greenbaum, H. Shirota, E. W. Castner, Jr., and J. F. Wishart, "A Nuclear Magnetic Resonance Study of the Dynamics of Imidazolium Ionic Liquids with -CH2Si(CH3)3 vs. -CH2C(CH3)3 substituents", J. Phys. Chem. B, 2007, 111(18), 4885-4893. doi: 10.1021/jp071755w

J. B. Issa, A. Salameh, E. W. Castner, Jr., J. F. Wishart, and S. S. Isied, "Conformational Analysis of the Electron Transfer Kinetics across Oligoproline Peptides Using N,N-dimethyl-1,4-benzenediamine Donors and Pyrene-1-sulfonyl Acceptors", J. Phys. Chem. B, 2007, 111, 6878-6886. doi: 10.1021/jp071599t

A. M. Funston, T. A. Fadeeva, J. F. Wishart, E. W. Castner Jr., "Fluorescence Probing of Temperature-Dependent Dynamics and Friction in Ionic Liquid Local Environments", J. Phys. Chem. B, 2007, 111(18), 4963-4977. doi: 10.1021/jp068298o. This paper was no. 9 on the Most-Cited Articles list for calendar 2007 (Mar. 31, 2008 data).

K. E. Steege, J. Wang, K. E. Uhrich, and E. W. Castner, Jr., "Local Polarity and Microviscosity in the Hydrophobic Cores of Amphiphilic Star-Like and Scorpion-Like Macromolecules", Macromolecules, 2007, 40(10), 3739-3748. doi: 10.1021/ma061779l

H. Shirota, J. F. Wishart, and E. W. Castner, Jr., "Intermolecular Interactions and Dynamics of Room Temperature Ionic Liquids That Have Silyl- and Siloxy-Substituted Imidazolium Cations", J. Phys. Chem. B, 2007, 111(18), 4819-4829. doi: 10.1021/jp067126o.

G. B. Shaw, C. D. Grant, H. Shirota, E. W. Castner Jr., G. J. Meyer, L. X. Chen, "Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I) bis-Phenanthrolines in Solution", J. Am. Chem. Soc., 2007, 129(7), 2147-2160. doi: 10.1021/ja067271f

H. Shirota and E. W. Castner, Jr., "Molecular Dynamics and Interactions in Aqueous and Dichloromethane Solutions of Polyvinylpyrrolidone", Journal of Chemical Physics, 125(3), 034904 (2006) (14 pages). doi: 10.1063/1.2208356

C. D. Grant, K. E. Steege, M. R. Bunagan, and E. W. Castner, Jr., "Microviscosity in Multiple Regions of Complex Aqueous Solutions of Poly(ethylene oxide) oxide)-poly(propylene oxide) oxide)-poly(ethylene oxide)", J. Phys. Chem. B, 2005, 109(47), 22273-22284. doi:10.1021/jp053929k

H. Shirota and E. W. Castner, Jr., "Why Are Viscosities Lower for Ionic Liquids with -CH2Si(CH3)3 vs.-CH2C(CH3)3 Substitutions on the Imidazolium Cations?", J. Phys. Chem. B, 2005 , 109(46), 21576-21585. doi:10.1021/jp053930j. This paper ranked no. 7 on the JPC B Hot Papers list, Sept. 2007.

H. Shirota and E. W. Castner, Jr., "Physical Properties and Intermolecular Dynamics of an Ionic Liquid Compared with its Isoelectronic Neutral Binary Solution", J. Phys. Chem. A, 2005, 109(42), 9388-9392.doi:10.1021/jp054664c This paper ranked no. 15 on the JPC A Most-Accessed Articles list, Fall 2005.

E. M. Olano, C. D. Grant, T. J. Norman, Jr., E. W. Castner, Jr., and J. Z. Zhang, "Photoluminescence Decay Dynamics and Mechanism of Energy Transfer in Undoped and Mn2+ Doped ZnSe Nanoparticles", Journal of Nanoscience and Nanotechnology, 5(9), 1492-1497 (2005). doi:10.1166/jnn.2005.315

H. Shirota, A. M. Funston, J. F. Wishart, and E. W. Castner, Jr., "Ultrafast Dynamics of Pyrrolidinium Cation Ionic Liquids", Journal of Chemical Physics, 122(18), 184512 (2005) (12 pages). doi:10.1063/1.1893797

C. D. Grant, M. R. DeRitter, K. E. Steege, T. A. Fadeeva, and E. W. Castner, Jr., "Fluorescence Probing of Interior, Interfacial, and Exterior Regions in Solution Aggregates of Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Triblock Copolymers", Langmuir, 2005, 21(5), 1745-1752. doi:10.1021/la047560m

E. W. Castner, Jr., review of J. Michael Hollas' "Modern Spectroscopy", 4th Edition, in J. Chem. Ed. (2005), 82(1), 43-44.

T. Ishida, P. J. Rossky, and E. W. Castner, Jr., "A Theoretical Investigation of the Shape and Hydration Properties of Aqueous Urea: Evidence for Nonplanar Urea Geometry", J. Phys. Chem. B, 2004,108(45), 17583-17590. doi:10.1021/jp0473218

Y. Sun, E. W. Castner Jr., C. L. Lawson, P. G. Falkowski, "Biophysical Characterization of Natural and Mutant Fluorescent Proteins Cloned from Zooxanthellate Corals", FEBS Letters 570 (2004) 175–183. doi:10.1016/j.febslet.2004.06.043

Alfred B. Roney, Brian Space, E. W. Castner, R. L. Napoleon and P. B. Moore, "A Molecular Dynamics Study of Aggregation Phenomena in Aqueous n-Propanol", J. Phys. Chem. B 2004, 108, 7389-7401. doi:10.1021/jp037922j

Alan K. Soper, Edward W. Castner, Jr., and Alenka Luzar, "Impact of Urea on Water Structure: a clue to its properties as a denaturant?", Biophysical Chemistry, 105, 649-666, 2003. doi:10.1016/S0301-4622(03)00095-4

R. J. Cave and E. W. Castner, Jr., “A Time-Dependent Density Functional Theory Investigation of the Ground and Excited States of Coumarins 102, 152, 153, and 343, J. Phys. Chem. A, 2002, 106, 12117-12123. doi:10.1021/jp026718d

R. J. Cave, K. Burke and E. W. Castner, Jr., "Theoretical Investigations of the Ground and Excited States of Coumarin 151 and Coumarin 120", J. Phys. chem. A, 2002, 106, 9294-9305. doi:10.1021/jp026071x

L. Frauchiger, H. Shirota, K. E. Uhrich, and E. W. Castner, Jr., "Dynamic Fluorescence Probing of the Local Environments within Amphiphilic Star-like Macromolecules", J. Phys. Chem. B, 2002, 106, 7463-7468. doi:10.1021/jp020746e

H. Shirota and E. W. Castner, Jr., "Ultrafast Dynamics in Aqueous Polymer Solutions: Polyacrylamide", J. Am. Chem. Soc., 2001, 123, 12877-12885. doi:10.1021/ja010290z

E. W. Castner, Jr., D. Kennedy, and R. J. Cave, "Solvent as Electron Donor: Donor/Acceptor Electronic Coupling Is a Dynamical Variable", J. Phys. Chem. A, 104 (13) 2869-2885 (2000). doi:10.1021/jp9936852 (cover picture for this issue!)

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