Professor and Head of Chemistry
Carnegie Mellon University
email: hjkim@cmu.edu
Phone: (412) 268-6489
Fax: (412) 268-1061
Office: Mellon Institute 512
Professor and Head of Chemistry
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.
| 2002–present | Head of Chemistry, Carnegie Mellon University |
| 2002–present | Professor 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 |
Y. Shim and H. J. Kim, MD Study of Solvation in the Mixture of a Room-Temperature Ionic Liquid and CO2, J. Phys. Chem. B 114, 10160–10170 (2010).
Y. Shim and H. J. Kim, Nanoporous Carbon Supercapacitors in an Ionic Liquid: A Computer Simulation Study, ACS Nano 4, 2345–2355 (2010). Also highlighted in NPG Asia Materials 2 (2010).
H. Kim, M. Y. Choi, H. J. Kim and M. Llinás, Conformational Dynamics and Ligand Binding in the Multi-Domain Protein PDC109, PLoS One 5(2): e9180 (2010).
D. Jeong, M. Y. Choi, H. J. Kim and Y. Jung, Fragility, Stokes-Einstein Violation and Correlated Local Excitations in a Coarse-grained Model of an Ionic Liquid, Phys. Chem. Chem. Phys. 12, 2001–2010 (2010).
Y. Shim and H. J. Kim, Adiabatic Electron Transfer in a Room-Temperature Ionic Liquid: Reaction Dynamics and Kinetics, J. Phys. Chem. B 113, 12964–12972 (2009).
N. R. Dhumal, H. J. Kim and J. Kiefer, Molecular Interactions in 1-Ethyl-3-methylimidazolium Acetate Ion Pair: A Density Functional Study, J. Phys. Chem. A 113, 10397–10404 (2009).
Y. Shim and H. J. Kim, On Dielectric Relaxation, Ion Conductivity, Solvent Rotation and Solvation Dynamics in a Room-Temperature Ionic Liquid, J. Phys. Chem. B 112, 11028–11038 (2008).
Y. Shim and H. J. Kim, MD Study of SN1 Reactivity of 2-Chloro-2-methylpropane in the Room-Temperature Ionic Liquid 1-Ethyl-3-methylimidazolium Hexafluorophosphate, J. Phys. Chem. B 112, 2637–2643 (2008).
Y. Shim and H. J. Kim, Electron Transfer Reactions in Supercritical Water, J. Phys. Chem. B 112, 585–594 (2008).
Y. Shim, D. Jeong, S. R. Manjari, M. Y. Choi, and H. J. Kim, Solvation, Solute Rotation and Vibration Relaxation, and Electron Transfer Reactions in Room-Temperature Ionic Liquids, Acc. Chem. Res. 40, 1130–1137 (2007).
S. R. Manjari and H. J. Kim, Free Energy, Entropy and Volume of Activation for Electron Transfer Reactions in a Polar Solvent, J. Chem. Phys. 125, 011101 (2006).