Theoretical and computational chemistry, equilibrium and nonequilibrium statistical mechanics, computer simulations, chemical reactions and spectroscopy in solution, green solvents, supercapacitors, multi-domain proteins
Most chemical reactions occur in a solution environment, which alters significantly free energies and dynamics (and sometimes reaction mechanisms) of reaction systems through short-range and Coulombic interactions, compared to the gas phase. A classic example is solvolysis of halo-alkanes. Their SN1 kinetics become accelerated by many orders of magnitude in solvents like water, compared to the elimination pathway in the gas-phase pyrolysis. Therefore the influence of dissolution, commonly referred to as “solvation effect”, is critical to understanding kinetics (e.g., rate constant) and thermodynamics (e.g., equilibrium constant) of solution-phase reactions. By employing analytic theory and modern computational techniques, we study solvation effects in homogeneous (i.e., bulk solvent) and heterogeneous (e.g., interface and nano-confinement) environments. Our primary focus is on chemical reactions involving charge shift (e.g., SN1 and electron transfer reactions) and related dynamics (e.g., dielectric relaxation and vibrational energy relaxation) in environmentally benign green solvents, in particular, room-temperature ionic liquids and supercritical water.
Electric double layer capacitors (EDLCs) offer a promising energy storage system thanks to their high energy density and good power performance. Using computational methods, we study EDLCs based on microporous carbon electrodes in ionic liquids and organic electrolytes. Our main effort is directed towards quantitation of how electrode properties such as size and shape of carbon micropores and electrolyte properties, e.g., ion size, density and conductivity, control the energy and power densities of EDLCs.
Conformational changes of multi-domain proteins usually have a crucial influence on their functions. An excellent example is the activation of plasminogen to plasmin, which plays a key role in fibrinolysis. While there is strong experimental evidence that its activation is accompanied by closed-to-open conformational changes, 3D structure of entire plasminogen is not well understood. To gain insight into this important problem, we are performing large-scale simulations in collaboration with the Llinas group. Our current thrust is to investigate specific bindings and interactions between domains of plasminogen using various simulation techniques.
|Years||Position or Degree|
|2002–present||Professor of Chemistry, Carnegie Mellon University|
|2002–2015||Head of Chemistry, Carnegie Mellon University|
|2001–2002||Interim Head of Chemistry, Carnegie Mellon University|
|1998–2002||Associate Professor of Chemistry, Carnegie Mellon University|
|1992–1998||Assistant Professor of Chemistry, Carnegie Mellon University|
|1988–1992||Postdoctoral research fellow, University of Colorado, Boulder|
|1988||Ph.D. State University of New York at Stony Brook|
|2008-present||KIAS Scholar, School of Computational Sciences, Korea Institute for Advanced Study|
|2007||Adjunct Professor of Physics, Korea University|
|2001||Visiting Associate Professor of Chemistry, University of Colorado, Boulder|
|2001||Distinguished Visiting Associate Professor of Physics, BK21, Seoul National University|
A Molecular Dynamics Study of Water Flow Across Multiple Layers of Pristine, Oxidized, and Mixed Regions of Graphene Oxide Jon A. L. Willcox and H. J. Kim, ACS Nano 2017, 11, 2187–2193.
Spectroscopic and MD Study of Dynamic and Structural Heterogeneities in Ionic Liquids Eric C. Wu, H. J. Kim and Linda A. Peteanu, J. Phys. Chem. B 2017, 12, 1100–1107.
A Mechanistic Insight into Organocatalytic Properties of Imidazolium-Based Ionic Liquids and a Positive Co-Solvent Effect on Cellulose Modification Reactions in an Ionic Liquid Ryohei Kakuchi, Ryo Ito, Shuhei Nomura, Hadi Abroshan, Kazuaki Ninomiya, Tomoyuki Ikai, Katsuhiro Maeda, H. J. Kim and Kenji Takahashi, RSC Adv. 2017, 7, 9423–9430.
Gold Nanoclusters Promote Electrocatalytic Water Oxidation at the Nanocluster/CoSe2 InterfaceShuo Zhao, Renxi Jin, Hadi Abroshan, Chenjie Zeng, Hui Zhang, Stephen D. House, Eric Gottlieb, H. J. Kim, Judith C. Yang and Rongchao Jin, J. Am. Chem. Soc. 2017, 139, 1077–1080.
CO2 capture in ionic liquid 1-alkyl- 3-methylimidazolium acetate: A concerted mechanism without carbene Fangyong Yan, Nilesh R. Dhumal and H. J. Kim, Phys. Chem. Chem. Phys. 2017, 19, 1361–1368.
A Molecular Dynamics Study of the Ionic Liquid, Choline Acetate Jon A. L. Willcox, Hyunjin Kim and H. J. Kim, Phys. Chem. Chem. Phys. 2016, 18, 14850–14858.
MD Study of Stokes Shifts in Ionic Liquids: Temperature Dependence Eric Wu and H. J. Kim, J. Phys. Chem. B 2016, 120, 4644–4653.
A Computer Simulation Study of Graphene Oxide Supercapacitors: Charge Screening Mechanism S.-W. Park, A. D. DeYoung, N. R. Dhumal, Y. Shim, H. J. Kim and Y. Jung, J. Phys. Chem. Lett. 2016, 7, 1180–1186.
Theoretical study of interactions of a Li+(CF3SO2)2N ion pair with CR3(OCR2CR2)nOCR3 (R = H or F)
Hadi Abroshan, Nilesh R. Dhumal, Youngseon Shim and Hyung J. Kim, Phys. Chem. Chem. Phys., 2016, 18, 6754–6762.
Molecular mechanism for the activation of Au25(SCH2CH2Ph)18 nanoclusters by imidazolium-based ionic liquids for catalysis
Hadi Abroshan, Gao Li, Jizhi Lin, Hyung J. Kim, Rongchao Jin, Journal of Catalysis, 2016, 337, 72–79
Molecular Interactions of a Cu-Based Metal Organic Framework with a Confined Imidazolium-Based Ionic Liquid: A Combined Density-Functional Theory and Experimental Vibrational Spectroscopy Study N. R. Dhumal, M. P. Singh, J. A. Anderson, J. Kiefer and H. J. Kim, J. Phys. Chem. C 2016, 120, 3295–3304.
On the Structural Stability of Ionic Liquid/IRMOF Composites: A Computational Study
H. Abroshan and H.J. Kim, Phys. Chem. Chem. Phys. 2015, 17, 6248–6254.
Experimental and Mechanistic Understanding of Aldehyde Hydrogenation Using Au25 Nanoclusters with Lewis Acids: Unique Sites for Catalytic Reactions
G. Li, H. Abroshan, Y. Chen, R. Jin and H.J. Kim, J. Am. Chem. Soc. 2015, 137, 14295–14304.