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Robert S. H. Liu Professor
(808) 956-5723 phone / (808) 956-5908 fax 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 publicationsFor 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 publicationsA more recent program carried out jointly with
Dr. A. E. Asato is the design of azulenic donor-acceptor chromophore in material science studies. Representative publicationsRepresentative Publications
1. P. O. Andersson, T. Gillbro, A. E. Asato & R. S. H. Liu, "Dual Singlet State Emission in a Series of Mini-Carotenes," J. Luminescence, 51, 11-20 (1992).
2. S. Ganapathy & R. S. H. Liu, "Polyenes 30. Quantum Chain Processes in Photoisomerization of the All-Trans, 7-Cis and 11-Cis Isomers of Retinal," J. Am. Chem. Soc., 114, 3459-3464 (1992).
3. R. S. H. Liu, E. Krogh, X.-Y. Li, D. Mead, L. U. Colmenares, J. R. Thiel, J. Ellis, D. Wong & A. E. Asato, "Analyzing the Red-shift Characteristics of Azulenic, Naphthyl, Other Ring-fused and Retinyl Pigment Analogs of Bacteriorhodopsin," Photochem. Photobiol., 58, 701-705 (1993).
4. R. S. H. Liu, "Photochemistry of Polyenes Related to Vitamin A," in "CRC Handbook of Organic Photochemistry and Photobiology," eds. W. M. Horspool & P. S. Song, CRC Press, 165-172, 1995.
5. L. U. Colmenares & R. S. H. Liu, "Fluorinated Phenylrhodopsin Analogs. Binding Selectivity, Restricted Rotation and 19F-NMR Studies," Tetrahedron, 52, 109-118 (1996).
6. A. E. Asato, R. S. H. Liu, V. P. Rao & Y. M. Cai, "Azulene-containing Donor-acceptor Compounds as Second-order Nonlinear Chromophores,"Tetrahedron Lett., 37, 419-422 (1996).
7. L. U. Colmenares, W. P. Niemczura, A. E. Asato & R. S. H. Liu, "A 19F NMR Study of Rhodopsin Analogs: Use of Vinylfluororetinal Chromophores," J. Phys. Chem., 100, 9175-9180 (1996).
8. R. S. H. Liu & A. E. Asato, "Making Organic Concepts Visible," J. Chem. Ed., 74, 783-784 (1997).
9. D. Hoishen, L. U. Colmenares, J. Liu, C. J. Simmons, G. Britton & R. S. H. Liu, "Fluorinated Analogs of the Carotenoprotein,
10. L. U. Colmenares, X-L. Zou, J. Liu, A. E. Asato, R. S. H. Liu, A. deLera & R. Alvarez, "11,12-Difluororhodopsin and Related Odd-Numbered Fluororhodopsins. The Use of JF,F for Following a Cis-trans Isomerization Process," J. Am. Chem. Soc., 121, 5803-5804 (1999).
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page last updated 16-November-1999
