Nien-Hui GeAssistant Professor, Chemistry Member, Chao Family Comprehensive Cancer Center
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Research Interests |
Physical and Analytical Chemistry, Chemical Physics and Biology | |
| URL | chem.ps.uci.edu/~nhge | |
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Academic Distinctions |
Margaret Jorgenson Memorial Fellowship, 1997 National Science Foundation CAREER Award, 2005 |
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| Appointments |
Postdoctoral Fellow, University of Pennsylvania Joined UCI faculty in 2002 |
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Research Abstract |
Detailed knowledge of molecular structures and dynamics in condense phases is essential to a complete and predictive understanding of chemical and biological processes. Our research program is directed to determine how molecular structures change in time, at equilibrium and during reactions. Topics of current interest include: the backbone and side chain conformation of peptides and proteins, kinetics of protein folding, and local structure and dynamics of liquids. These endeavors lead us to devise new techniques in nonlinear spectroscopy that can provide detailed information on the time dependence of intra- and intermolecular vibrational couplings, and hence structural changes as they evolve. Ultrafast multidimensional multicolor IR spectroscopy. We are exploiting new experimental techniques that are vibrational analogues of multidimensional NMR. The extension beyond a single dimension gives these techniques the ability to disentangle structural information from complex spectra where the couplings, correlations, and relative angular orientations between structural units are revealed as "cross peaks". Moreover, the picosecond time resolution of multidimensional IR makes it an ideal structural probe for short-lived intermediates in chemical or biological processes once initiated by external triggers. The necessary science of truly multidimensional multicolor IR spectroscopy is being developed in our laboratory. Experimental results are compared to computer simulations to bring out atomic level understanding of the processes in question. Biomolecular structure determination and condensed matter dynamics. We are applying multidimensional IR to the study of complex systems such as peptides, proteins, liquids, membranes, and their composite interfaces. Structural distributions, evolutions, and their environmental dependence are investigated. Dynamics of vibrational relaxation, molecular reorientation, and intermode vibrational energy transfer are studied. These processes are important for the interpretation of multidimensional IR spectra. Strategic incorporation of isotope labels and vibrational markers are used to zoom into atomic moieties of particular interest.  Research Opportunities: Graduate, Undergraduate, and Postdoctoral Research positions available |
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| Publications | "Toward Detecting the Formation of a Single Helical Turn by 2D IR Cross-Peaks between the Amide-I and -II modes," H. Maekawa, M. De Poli, A. Moretto, C. Toniolo, and N.-H. Ge, J. Phys. Chem. B. 2009, 113, 11775. [link] [e-reprint without subscription] | |
| "Sensitivity of 2D IR Spectra to Peptide Helicity: a Concerted Experimental and Simulation Study of an Octapeptide," N. Sengupta, H. Maekawa, W. Zhuang, S. Mukamel, D. J. Tobias and N.-H. Ge, J. Phys. Chem. B. 2009, 113, 12037. [link] [e-reprint without subscription] | ||
| "Chain Length Dependence of Two-Dimensional Infrared Spectral Pattern Characteristic to 310-Helix Peptides," Maekawa, F. Formaggio, C. Toniolo, and N.-H. Ge, Ultrafast Phenomena XVI , in press (2009) | ||
| "Couplings between Peptide Linkages across a 310-Helical Hydrogen Bond Revealed by Two-Dimensional Infrared Spectroscopy," H. Maekawa, M. De Poli, C. Toniolo, and N.-H. Ge, J. Am. Chem. Soc. 2009, 131, 2042. [link] [e-reprint without subscription] | ||
| "Onset of 310-Helical Secondary Structure in Aib Oligopeptides Probed by Coherent 2D IR Spectroscopy," H. Maekawa, F. Formaggio, C. Toniolo, and N.-H. Ge, J. Am. Chem. Soc. 2008, 130, 6556. [link] [e-reprint without subscription] | ||
| "Two-Dimensional Infrared Spectral Signatures of 310- and alpha-Helical Peptides," H. Maekawa, C. Toniolo, A. Moretto, Q. Broxterman, and N.-H. Ge, J. Phys. Chem. B 2007, 111, 3222. [link] [e-reprint without subscription] | ||
| Conformations of N-Acetyl-L-Prolinamide by Two-Dimensional Infrared Spectroscopy, Sul S, Karaiskaj D, Jiang Y, and Ge N-H, J. Phys. Chem. B 2006, 110, 19891. [link] [e-reprint without subscription] | ||
| "Resolving Conformations of Acetylproline-NH2 by coherent two-dimensional infrared spectroscopy," in Ultrafast Phenomena XIV , Karaiskaj D, Sul S, Jiang Y, Ge N-H (eds: T Kobayashi, T Okada, T Kobayashi, KA Nelson, S.De Silvestri), Spring-Verlag, p. 545 (2005) | ||
| Different Spectral Signatures of Octapeptide 310- and alpha-Helices Revealed by Two-Dimensional Infrared Spectroscopy, Maekawa H, Toniolo C, Moretto A, Broxterman Q, and Ge N-H, J. Phys. Chem. B 2006, 110, 5834. [link] [e-reprint without subscription] | ||
| "Local Structure and Dynamics of Liquid Acetone by Heterodyned 2D IR Spectroscopy." in Ultrafast Phenomena XIII, Ge N-H, Zanni MT, Hochstrasser RM (eds.: MM Murnane, NF Scherer, RJD Miller, AM Weiner), Spring-Verlag, pp. 592-594 (2003) [pdf] | ||
| "Femtosecond Two-Dimensional Infrared Spectroscopy: IR-COSY and THIRSTY." Ge N-H, Hochstrasser RM, PhysChemComm 2002, 5, 17. [link] | ||
| "Effects of Vibrational Frequency Correlations on Two-Dimensional Infrared Spectra." Ge N-H, Zanni, MT, Hochstrasser RM, J. Phys. Chem. A 2002, 106, 962. [link] | ||
| "2D IR Spectroscopy Can Be Designed to Eliminate the Diagonal Peaks and Exhibit Only the Cross Peaks Needed for Structure Determination." Zanni MT, Ge N-H, Kim YS, Hochstrasser RM, Proc. Natl. Acad. Sci. USA 2001, 98, 11265. | ||
| "Femtosecond Studies of Electron Dynamics at Interfaces." Ge N-H, Wong CM, Harris CB, Acc. Chem. Res. 2000, 33, 111. [link] | ||
| "Femtosecond Dynamics of Electron Localization at Interfaces." Ge N-H, Wong CM, Lingle RL, McNeill JD, Gaffney KJ, Harris CB, Science 1998, 279, 202. [link] | ||
| "Dynamics and Spatial Distribution of Electrons in Quantum Wells at Interfaces Determined by Femtosecond Photoemission Spectroscopy," McNeill JD, Lingle RL, Ge N-H, Wong CM, Harris CB, Phys. Rev. Lett. 1997, 79, 4645. | ||
| "Femtosecond Dynamics of Electrons on Surfaces and at Interfaces." Harris CB, Ge N-H, Lingle RL, McNeill JD, Wong CM, Annu. Rev. Phys. Chem. 1997, 48, 711. | ||
| Femtosecond Studies of Electron Tunneling at Metal-Dielectric Interfaces, Lingle RL, Ge N-H, Jordan RE, McNeill JD, and Harris CB, Chem. Phys. 1996, 205, 191. | ||
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Professional Societies |
American Chemical Society American Physical Society Optical Society of America American Association of Advanced Science |
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| Research Centers | Chao Family Comprehensive Cancer Center | |
| NSF CCI at UCI - CaSTL: Chemistry at the Space-Time Limit | ||
| Link to this profile | http://www.faculty.uci.edu/profile.cfm?faculty_id=4907 | |
| Last updated | 09/17/2009 | |
