Our research interests are in physical chemistry and chemical physics, focusing in the general area of state-selected and state-to-state spectroscopy and dynamics. By employing high resolution photoionization and photoelectron methods, we are actively engaging in the study of chemical structure, energetics, and reactivity of ions and neutrals. We are particularly interested in developing new experimental methods to advance these research fields. Recent advances include the introduction of two-color infrared-vacuum ultraviolet (IR-VUV) and VUV-VUV laser photoexcitation schemes for photoionization and photodissociation studies. We have also succeeded in implementing a novel high-resolution VUV pulsed field ionization method for the preparation ions in single rovibronic states, which has allowed the examination of translational, rotational, vibrational, and electronic energy effect on chemical reactivity. These new methods are being applied to the study of neutrals and ions of relevance to combustion, catalysis, atmospheric, planetary, and interstellar chemistry.
Education, Awards and Professional Highlights
- Visiting Distinguished Chair Professor, National Taiwan University (2013)
- Associate Editor, Journal of Chemical Physics (July 2010-December 2014)
- Dean of Science, The Chinese University of Hong Kong (September 2009-August 2012)
- Associate Editor, Chinese Journal of Chemical Physics (2006-present)
- Elected Fellow, American Association for the Advancement of Science (2005)
- Distinguished Professor, UC Davis (2001-present)
- Senior Humboldt Research Award (1998)
- Senior Fellow, Japanese Society for Promotion of Science (1997)
- Distinguished Professor of Liberal Arts and Sciences, Iowa State University (1996-2001)
- Iowa Regents Award for Faculty Excellence (1994)
- Editor-in-charge, Advances Series in Physical Chemistry, World Scientific Book Series (1993-present)
- Elected Fellow, American Physical Society (1993)
- Founding Chairman of the Gordon Research Conference Series, Structures, Energetics and Reaction Dynamics of Gaseous Ions, Ventura, California (1991-present)
- Honorary Professor, Zhengzhou University, China (1985)
- Camille and Henry Dreyfus Teacher-Scholar (1982)
- Alfred P. Sloan Fellow (1981)
- Assistant (1977), Associate (1982) and Full Professor of Chemistry (1986-1996), Iowa State University
- Ph.D. University of California, Berkeley (1976)
- B. S. Chung Chi College, The Chinese University of Hong Kong (1971)
- Yuntao Xu, Bo Xiong, Yih Chung Chang, and C. Y. Ng, “A quantum-rovibrational-state-selected study of the H2O+(X2B1; v1+v2+v3+; N+Ka+Kc+ ) + CO reaction in the collision energy range of 0.05-10.00 eV: translational, rotational, and vibrational energy effects”, Physical Chemistry Chemical Physics, 19, 9778-9789 (2017). [DOI: 10.1039/C7CP00937B]
- Yih Chung Chang, Bo Xiong, B. Ruscic, and C. Y. Ng, “A vacuum ultraviolet laser pulsed field ionization-photoion study of methane (CH4): determination of the bond energies for CH4 and CH4+ with unprecedented precision”, Physical Chemistry Chemical Physics, 19, 9592-9605 (2017). [DOI: 10.1039/c6cp08200a]
- Yuntao Xu, Bo Xiong, Yih Chung Chang, and C. Y. Ng, “Isotopic and quantum rovibrational-state effects for the ion-molecule reaction H2O+(X2B1: v1+v2+v3+; N+Ka+Kc+) + HD in the collision energy range of 0.03-10.00 eV”, Physical Chemistry Chemical Physics 19, 8694-8705 (2017). [DOI: 10.1039/C7CP00295E]
- Yi Pan, Zhihong Luo, Yih-Chung Chang, Kai-Chung Lau, and C. Y. Ng, “High-level ab initio predictions for the ionization energies, bond dissociation energies, and heats of formation of titanium oxides and their cations (TiOx/TiOx+, x = 1 and 2)”, J. Phys. Chem. A. 121, 669-679 (2017). [DOI: 10.1021/acs.jpca.6b09491]
- Hongwei Song, Anyang Li, Hua Guo, Yuntao Xu, Bo Xiong, Yih-Chung Chang, and C. Y. Ng, "Comparison of Experimental and Theoretical Quantum-state-selected Integral Cross Sections for the H2O+ + H2 (D2) Reactions in the Collision Energy Range of 0.04-10.00 eV", Phys. Chem. Chem. Phys.18, 22509 (2016). DOI: 10.1039/c6cp04598g
- Yuntao Xu, Bo Xiong, Yih Chung Chang, and C. Y. Ng, "Absolute integral cross sections for the state-selected ion-molecule reaction N2+(X2Σg+; v+ = 0-2) + C2H2 in the collision energy range of 0.03-10.00 eV", Astrophysical Journal,827, 17 (2016). doi:10.3847/0004-637X/827/1/17
- Zhou Lu, Hong Gao, Yuntao Xu, Lei Yang, Chow-Shing Lam, Yanice Benitez, and C. Y. Ng, "High-resolution threshold photoelectron spectroscopy by vacuum ultraviolet laser velocity-map-imaging method", Chinese J. Chem. Phys. (invited), 29, 59-69 (2016). DOI:10.1063/1674-0068/29/cjcp1512247
- Yu Song, Hong Gao, Yih Chung Chang, D. Hammoutène, H. Ndome, M. Hochlaf, William M. Jackson, and C. Y. Ng, "Quantum-state-control of product branching ratios in vacuum ultraviolet photodissociation of N2", Astrophysical Journal, 819, 23 (2016). DOI:10.3847 /0004-637X/819/1/23.
- Yih-Chung Chang, Zhihong Luo, Zheng Zhang, Qing-Zhu Yin and C. Y. Ng ""Rotationally resolved state-to-state photoionization and photoelectron study of vanadium carbide and its cation (VC/VC+)", Phys. Chem. Chem. Phys. 17, 9780-9793 (2015), DOI: 10.1039/C5CP00371G.
- Zhihong Luo, Yih-Chung Chang, Zheng Zhang, and C. Y. Ng "Rotationally resolved state-to-state photoelectron study of zirconium monoxide cation (ZrO+)", Molecular Physics, 113, 2528 (2015). http://dx.doi.org/10.1080/00268976.2015.1021726.
- Cheuk-Yiu Ng, "State-to-state spectroscopy and dynamics of ions and neutrals by photoionization and photoelectron methods", Annual Review Physical Chemistry, 65, 197-224 (2014).
- Zhou Lu, Yih-Chung Chang, Qing-Zhu Yin, C. Y. Ng, and W. M. Jackson, "Evidence for direct molecular oxygen production in CO2photodissociation", Science 346, 61 (2014).