Affiliated Faculty

Summary of Expertise

Theoretical chemistry, molecular dynamics of chemical reactions in liquids and at interfaces

Research Interests

Theoretical Chemistry, Molecular Dynamics of Chemical Reactions in Liquids, Theory of Energy Transfer and Relaxation in the Condensed Phase, Computational Methods Development

The research activity in our group is focused on the theoretical study of the microscopic dynamics of chemical reactions in the condensed phase. This includes chemical reactions in bulk solution and at surfaces. The major goal is to understand the dynamic structural and energetic changes in the medium that help drive the chemical reaction, as well as the way in which the medium changes the intrinsic chemical forces from their bare gas-phase values. To do this we use a variety of computer simulation methods and powerful multiprocessing workstations. Molecular dynamics simulation is used to reveal time-dependent motion and energy flow in the solvent and the reagents for chemical reactions in solution, and Monte Carlo simulation is used to understand equilibrium properties of the system. An important aspect of the approach is a close tie with experimental results, in particular, time-resolved spectroscopy and kinetic measurements. During the last few years, the research efforts have been focused on the study of chemical dynamics at fluid interfaces, including liquid/vapor, liquid/liquid and liquid/solid interfaces. This research has been motivated by the fundamental and practical importance of these systems, by a wealth of experimental data generated using new techniques and by the fact that very little has been done in this area to facilitate a theoretical understanding at the molecular level.
An important part of our research effort is directed toward the development of new simulation techniques. In particular, there is a need for improved methods for studying electronic transitions in solution and in surface reactions, and more efficient techniques for the simulation of complex macromolecular systems. Other areas include the development of simple analytical models that are able to capture the essence and important physical properties of the system, in addition to providing a simple language to describe the complex data (and graphic images) that the computer can provide.

Biography, Education and Training

Ph.D. Theoretical Chemistry

Postgraduate training: University of Pennsylvania, Philadelphia, PA

University of California, San Diego, CA

Honors, Awards and Grants

2016                     Distinguished professor, Chemistry and Biochemistry

2013                     Fellow, American Physical Society

2012                     Fellow, American Association for the Advancement of Science

1985 – 1987         Weizmann Postdoctoral Fellow

Selected Publications

Recent Publications

[156] Pan Sun, Erik A. Binter, Trung Vo, Ilan Benjamin, Mrinal K. Bera, Binhua Lin, Wei Bu and Mark L. Schlossman, "Relevance of surface adsorption and aqueous complexation for the separation of Co(II), Ni(II) and Fe(III)", J. Phys. Chem. B 127, 3505-3515 (2023). link

[155] Zhu Liang, Trung Vo, Karl J. Schweighofer, Ilan Benjamin and Mark L. Schlossman, "DEHP- extractant binding to trivalent lanthanide Er3+: Fast binding accompanies by concerted angular motion of hydration water", J. Chem. Phys. 158, 134715 (2023). link

[154] Shane W. Devlin, Ilan Benjamin and Richard J. Saykally, "On the mechanisms of ion adsorption to aqueous interfaces: air-water vs. oil-water", PNAS, 119 (42), 1-7 (2022). link

[153] I. Benjamin, " Structure, Thermodynamics, and Dynamics of Thiocyanate Ion Adsorption and Transfer across the Water/Toluene Interface", J. Phys. Chem. B, 126, 5706-5714 (2022). link

[152] Pan Sun, Erik A. Binter, Zhu Liang, M. Alex Brown, Artem V. Gelis, Ilan Benjamin, Mrinal K. Bera, Binhua Lin, Wei Bu and Mark L. Schlossman, " Antagonistic Role of Aqueous Complexation in the SolventExtraction and Separation of Rare Earth Ions", ACS Cent. Sci, 7, 1908-1918 (2021).link

[151] J. J. Karnes and I. Benjamin, "Deconstructing the Local Intermolecular Ordering and Dynamics of Liquid Chloroform and Bromoform", J. Phys. Chem. B,125, 3629-3637(2021). link

[150] I. Benjamin, "Molecular Dynamics Studies on the Effect of Surface Roughness and Surface Tension on the Thermodynamics and Dynamics of Hydronium Ion Transfer Across the Liquid/Liquid Interface", J. Phys. Chem. B, 124, 8711-8718(2020). link

[149] J. J. Karnes, N. Villavicencio and I. Benjamin, "Transfer of Erbium ion across the water/dodecane interface: Structure and thermodynamics via MD simulations", Chem. Phys. Letters, 737, 136825(2019). link

[148] I. Benjamin, "Hydronium Ion at the Water/1,2-dichloroethane interface: Structure, Thermodynamics and Dynamics of Ion Transfer", J. Chem. Phys. , 151, 094701(2019). link

[147] Z. Liang, W. Bu, K. J. Schweighofer, D. J. Walwark Jr., J. S. Harvey, G. R. Hanlon, D. Amoanu, C. Erol, I. Benjamin and M. L. Schlossman, "Nanoscale view of assisted ion transport across the liquid-liquid interface", PNAS , 116, 18227-18232 (2018). link

[146] J. J. Karnes and I. Benjamin, "Miscibility at the immiscible liquid/liquid interface: A molecular dynamics study of thermodynamics and mechanism", J. Chem. Phys. , 148, 034707(2018). link

[145] J. J. Karnes and I. Benjamin, "On the local intermolecular ordering and dynamics of liquid chloroform", J. Mol. Liq. , 248, 121-126(2017). link

[144] J. J. Karnes and I. Benjamin,"SN2 Reaction rate enhancement by beta-Cyclodextrin at the liquid/liquid interface", J. Phys. Chem. C. , 121, 19209-19217(2017).link

[143] J. J. Karnes and I. Benjamin, "Structure and dynamics of host/guest complexation at the liquid/liquid interface: implications for inverse phase transfer catalysis", J. Phys. Chem. C. , 121, 4999-5011(2017). link

[142] J. J. Karnes and I. Benjamin, "Geometric and energetic considerations of surface fluctuations during ion transfer across the water-immiscible organic liquid interface", J. Chem. Phys., 145, 014701 (2016). link

[141] J. J. Karnes, E. A. Gobrogge, R. A. Walker and I. Benjamin, "Unusual structure and dynamics at silica/methanol and silica/ethanol interfaces-A molecular dynamics and nonlinear optical study", J. Phys. Chem. B. , 119, 5086-5092 (2015). link

[140] J. J. Karnes and I. Benjamin, "Mechanism and dynamics of molecular exchange at the silica/binary solvent mixtures interface", J. Phys. Chem. A. , 119, 12073-12081 (2015). link

[139] J. Chief Elk and I. Benjamin, "beta-Cyclodextrin at the water/1-bromobutane interface: molecular insight into reverse phase transfer catalysis", Langmuir , 31, 5086-5092 (2015). link

[138] I. Benjamin, "Reactivity and dynamics at liquid interfaces", in Reviews in Computational Chemistry, A. L. Parrill and K. B. Lipkowitz Eds., 28, 205-313 (2015). link

[137] I. Benjamin, "Correlating Structure and Thermodynamics of Hydrophobic-Hydrophilic Ion Pairs in Water", Chem. Phys. Lett. , 625, 139-142 (2015). link

[136] I. Benjamin, "Reaction Dynamics at Liquid Interfaces", Annu Rev. Phys. Chem. , 66, 165-188 (2015). link