Robert S. H. Liu

Professor

University of Hawaii at Manoa
Department of Chemistry
2545 McCarthy Mall
Honolulu, HI 96822-2275

Phone: (808) 956-5723
Fax: (808) 956-5908
Email: rliu@gold.chem.hawaii.edu

 
 

 Robert Liu received his Ph.D. degree from California Institute of Technology. After four years as a research chemist at duPont, he joined the chemistry department at UH in 1968. He has been named an Alfred P. Sloan Fellow (1969-71), a John Simon Guggenheim Fellow (1974-5), a UH Fujio Matsuda Scholar (1985) and received UH Regents' Medals for excellence in Research in (1986) and in Teaching (1988). He has been given the NSF Creativity Award (1987-9) and the NIH Merit Award (1992-5). He was a 60th birthday honoree at the ACS National Meeting at Boston, 1998. Other background

 
 

Our current research activities center around vitamin A, carotenoids and other polyenes, including mechanisms of photoisomerization, stereoselective synthesis of isomers of vitamin A and carotenoids, bioorganic and FNMR studies of retinal-binding protein analogs and designing unusual polyenes for their unique optical or other properties.

A significant amount of time has been devoted to studies of visual pigments, bacteriorhodopsin and sensory rhodopsin analogs. Retinal analogs are designed and prepared for better understanding of protein-substrate interactions, for promoting unusual properties of binding complexes such as Near IR absorbing pigment analogs or for introduction of reporting groups (such as 19F labels). Representative publications

Recently, this study has been extended to fluorinated carotenoids and the corresponding caroteno-protein complexes. Representative publications

For photochemical studies, the emphasis has been on factors controlling regioselective isomerization as a way of introducing new geometry, quantum chain processes for enhancing efficiencies of reactions or for energy conversion and the effect of medium in directing regio- or stereo-selectivity of reactions. Representative publications

A more recent program carried out jointly with Dr. A. E. Asato is the design of azulenic donor-acceptor chromophore in material science studies. Representative publications

 
 

Representative Publications

  • R. S. H. Liu & G. S. Hammond, "The Case of Medium-Dependent Dual Mechanisms for Photoisomerization: One-Bond-Flip and Hula-Twist," Proc. Natl. Acad. Sci., USA, 97, 11153-11158 (2000).
  • R. S. H. Liu, "Photoisomerization by Hula-Twist: A Fundamental Supramolecular Photochemical Reaction," Acc. Chem. Res., 34, 555-562 (2001).
  • R. S. H. Liu, "Colorful Azulene and its Equally Colorful Derivatives," J. Chem. Ed., 79, 183-185 (2002).
  • Y. Imamoto, T. Kuroda, M. Kataoka, S. Shevyakov, G. Krishnamoorthy & R. S. H. Liu, "Photoisomerization by Hula-twist.  2,2'-Dimethylstilbene and a Ring-fused Analogue," Angew. Chem. Int. Ed., 42, 3630-3633 (2003).
  • R. S. H. Liu & G. S. Hammond, "Photochemical Reactivity of Polyenes:  From Dienes to Rhodopsin, from Microseconds to Femtoseconds," Photochem. Photobiol. Sci., 2, 835-844 (2003). 
  • R. S. H. Liu & A. E. Asato, "Tuning the Color and Excited State Properties of the Azulenic Chromophore: NIR Absorbing Pigments and Materials," J. Photochem. Photobiol. C, 4, 179-194 (2003).
  • R. S. H. Liu & L. U. Colmenares, "The Molecular Basis for the High Photosensitivity of Rhodopsin," Proc. Natl. Acad. Sci., USA, 100, 14639-14644 (2003).
  • L. Y. Yang, R. S. H. Liu, K. J. Bowman, N. L. Wendt & J. Liu, "New Aspects of Diphenylbutadiene Photochemistry.  Regioselective Hula-twist Photoisomerization," J. Am. Chem. Soc., 127, 2404-2405 (2005).
  • R. S. H. Liu, "You're Repulsive!" - Teaching VSEPR in a Not-so-elegant Way," J. Chem. Ed., 82, 558-560 (2005). 
  • R. S. H. Liu & G. S. Hammond, "Reflection on Medium Effects on Photochemical Reactivity," Acc. Chem. Res., 38, 396-403 (2005).
  • R. S. H. Liu, G. S. Hammond & T. Mirzadegan, "On a Possible Role of 11-cis Retinal Conformation in Controlling the Dual Decay Processes of Excited Rhodopsin," Proc. Natl. Acad. Sci., USA, 102, 10783-10787 (2005).
  • R. S. H. Liu, L.-Y. Yang & J. Liu, “Mechanisms of Photoisomerization in Confined Media.  From Polyene Chromophores in Organic Glasses to Protein Binding Cavities,” Photochem. Photobiol., 83, 0000-0000 (2006).
Last updated 07/14/06