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  • ȿö   Professor
  • Physical Chemistry and Biophysics
  • Ph.D. 2001, California Institute of Technology
  • WEBPAGE : http://time.kaist.ac.kr/
  • E-MAIL : Hyotcherl.Ihee@kaist.ac.kr
  • Tel/Office : 042-350-2844 (Office), 2884 (Lab) / 505(E6-6) (Room)

Contact information

Tel: (office) +82-42-350-2844, (lab) +82-42-350-2884
Location: (office) Room 505 (Bldg. E6-6), (lab) Room 513, 514 (Bldg. E6-6)
Fax: +82-42-350-2810


Ph. D. Chemistry, California Institute of Technology June, 2001(Graduate Advisor: Prof. Ahmed H. Zewail)
B. S. Chemistry, KAIST(Korea Advanced Institute of Science and Technology) February, 1994
Graduated with highest honor (2nd out of 550 graduates)


Professor, Department of Chemistry, KAIST 2009 - present
Associate Professor, Department of Chemistry, KAIST 2006 - 2009
Assistant Professor, Department of Chemistry, KAIST 2003 - 2006
Group Leader, Center for Nano-materials & Chemical Reactions 2012 - present
(Institute for Basic Science)
Director, Center for Time-Resolved Diffraction 2007 - 2012
(National Creative Research Initiatives by MOST/KOSEF)
Postdoctoral Scholar (Prof. K. Moffat) 2001 - 2003
Department of Biochemistry &Molecular Biology, University of Chicago
Postdoctoral Scholar (Prof. A. H. Zewail) 2001
Department of Chemistry, California Institute of Technology
Graduate Research Assistant (Prof. A. H. Zewail) 1994 - 2001
Department of Chemistry, California Institute of Technology
Research Advisor: Prof. A. H. Zewail
Research Collaborator: Prof. W. A. Goddard, III

Academes and Society

American Crystallographic Association 2008 - present
American Association for the Advancement of Science 1998 - present
American Physical Society 1996 - present
American Chemical Society 1994 - present


Morino Lectureship Award (MEST) 2011
Best Lecturer Award (KAIST Chemistry Department) 2010
Lectureship Award from Chemical Society of Japan 2009
KAIST Teaching Excellence Award 2009
KAIST Teaching Excellence Award 2008
Best Oral Paper at 10th Eurasia Conference on Chemical Sciences 2008
Best Lecturer Award (KAIST Chemistry Department) 2006
10th Young Scientist Award (MOST/KIAS) 2006
16th KOFST Best Paper Award 2006
KAIST Academic Excellence Award 2006
Damon Runyon Cancer Research Fellow 2002 - 2003
Graduated with highest honors from KAIST 1994


Brief Introduction

One of the most fundamental questions in biology, chemistry, and physics is how the molecules interact, so called, reaction mechanisms. Our laboratory strives to understand the reaction mechanisms in molecular detail in gas phase, solution phase, and solid phase spanning amorphous phase, polycrystalline and single crystals. Traditionally, femtosecond spectroscopy has been used to achieve this goal, however, spectroscopic data, in most cases, fail to provide direct information on the structural changes such as bond lengths and bond angles. To remedy this, we combine the traditional femtoscience with direct structural tools such as diffraction, EXAFS, and NMR. These techniques can be applied to a wide range of systems, encompassing small molecules, nano-scale complexes, and macromolecules such as polymers, proteins and DNA. A typical experiment is conducted in a pump-probe manner; an optical pulse such as femtosecond laser pulse is directed to the sample of interest to initiate a desired reaction, and after a well-defined time delay, a probing pulse such as an ultrashort x-ray pulse is sent to the sample undergoing a reaction. Then, the signal resulted from the interaction of the reacting system and the probing pulse captures the molecular actions in real time. Since the measured signal (in this case, diffraction signal) is a function of molecular structures, the time-dependant data at various time delays contains a clue to the molecular reaction mechanisms and a novel data analysis of the time-resolved signal finally reveals the mechanism.

Research topics

Molecular structural Dynamics
Chemical Reaction Dynamics
Protein structural Dynamics
Ultrafast X-ray Diffraction
Ultrafast Electron Diffraction
Ultrafast spectroscopy

Representative publications

"Volume-conserving trans-cis isomerization pathways in photoactive yellow protein visualized by picosecond X-ray crystallography", Y. O. Jung, J. H. Lee, J. Kim, M. Schmidt, K. Moffat, V. Srajer, H. Ihee*, Nature Chemistry, in press (2013)
"Direct observation of cooperative protein structural dynamics of homodimeric hemoglobin from 100 picoseconds to 10 milliseconds with pump-probe X-ray solution scattering", K. H. Kim, S. Muniyappan, K. Y. Oang, J. G. Kim, S. Nozawa, T. Sato, S. Koshihara, R. Henning, I. Kosheleva, H. Ki, Y. Kim, T. W. Kim, J. Kim, S. Adachi, H. Ihee*, J. Am. Chem. Soc., 134, 7001-7008 (2012).
"Protein structural dynamics of photoactive yellow protein in solution revealed by pump-probe X-ray solution scattering", T. W. Kim, J. H. Lee, J. Choi, K. H. Kim, L. van Wilderen; L. Guerin, Y. Kim, Y. O. Jung, C. Yang, J. Kim, M. Wulff, J. van Thor*, H. Ihee*, J. Am. Chem. Soc., 134, 3145-3153 (2012)
"Visualizing Solution-Phase Reaction Dynamics with Time-Resolved X-ray Liquidography", H. Ihee*, Acc. Chem. Res., 42, 356-366 (2009)
"Tracking the structural dynamics of proteins in solution using time-resolved wide-angle X-ray scattering.", M. Cammarata*, M. Levantino , F. Schotte, P. A. Anfinrud, F. Ewald, J. Choi, A. Cupane, M. Wulff, H. Ihee*, Nature Methods, 5, 881-887 (2008)
Initial Catalyst-Substrate Association Step in Enyne Metathesis Catalyzed by Grubbs Ruthenium Complex Probed by Time-Dependent Fluorescence Quenching", J.-H. Sohn*, K. H. Kim, H. Y. Lee, Z. S. No, H. Ihee*, J. Am. Chem. Soc., 130, 16506-16507 (2008)
"Ultrafast X-ray diffraction of transient molecular structures in solution", H. Ihee*, M. Lorenc, T. K. Kim, Q. Y. Kong, M. Cammarata, J. H. Lee, S. Bratos, M. Wulff, Science, 309, 1223-1227 (2005)