Time: 9:00 AM, October 29

Place: Room C305, IHEP Main Building

Moderator: Academician CHAI Zhifang

Speech 1

Title: The Development and Properties of High Affinity Actinide Sequestering Agents

Speaker:Kenneth Raymond（University of California, Berkeley）

Abstract:

Bacteria produce small molecule chelators called siderophores for the selective and powerful sequestration of ferric ion. We have used these natural chelators as models for the production of actinide-specific sequestering agents. 

A recent octadentate macrocyclic ligand for Th(IV) has a stability constant 1053. Recent examples of such determinations and the applications in areas of biomedical research will be described.

Circularly polarized luminescence (CPL) is a rarely used spectroscopy that discriminates between luminescent chiral complexes. Using several different chiral chelating ligands, the world’s first actinide circularly polarized luminescence (CPL) spectra with curium (III) complexes have been reported. This provides a new tool to probe the chemical and bonding differences between the 4f and 5f elements. 

About the speaker:

Prof. Kenneth Raymond obtained his PhD in inorganic chemistry at Northwestern University in 1968. He became Full Professor in 1978, Chair of the Department of Chemistry in 1993, and Chancellor’s Professor of University of California, Berkeley in 2006. He was elected to the National Academy of Sciences in 1997 and to the American Academy of Arts and Sciences in 2001. His research interests include (1) the coordination chemistry and mechanisms of microbial iron transport and the mechanism of human iron storage and transport, (2) the design, synthesis and coordination properties of sequestering agents specific for individual metal ions, especially iron, the lanthanides and the actinides, and (3) bioinorganic and coordination chemistry, supramolecular chemistry of metal complexes. He has published over 526 papers and edited books and received over 22340 citations.

Speech 2

Title: Soft X-ray Synchrotron Radiation Studies of Actinide Materials

Speaker: David K. Shuh（Lawrence Berkeley National Laboratory）

Abstract:

Synchrotron radiation (SR) methods have been employed to investigate the chemistry and physics of a wide range of topics in actinide science for several decades. A specific emphasis has been on actinide complexes with light atom constituents that can be probed by near-edge X-ray absorption spectroscopy (NEXAFS) at the K-edge of ligand atoms to yield quantitative bonding information. The actinide soft X-ray spectromicroscopy approach has been developed over the past decade using a scanning transmission X-ray microscope (STXM) at the Molecular Environmental Science Beamline 11.0.2 of the Advanced Light Source at the LBNL. The MES STXM has been used to obtain K-edge NEXAFS spectra from C, N, O, and F atom constituents in a range of coordination complexes that include actinides. An essential component of these studies is the theoretical efforts that enable the understanding of the NEXAFS spectra and help confirm the experimental results. Complementing the STXM NEXAFS approach are investigations of actinide materials that employ X-ray emission spectroscopy (XES) to obtain information from filled states and the complementarity of XES to the STXM NEXAFS approach will be described. As STXM and XES approaches used for conducting actinide science investigations in the soft X-rays have progressed, innovations in both methods hold the promise to expand the scope and breadth of actinide science studies, especially in the area of chemical bonding, that can be unraveled with soft X-rays in the future.   

About the speaker:

Dr.David K. Shuh is currently the Director of The Glenn T. Seaborg Center (GTSC) of Lawrence Berkeley National Laboratory, Senior Scientist and Principal Investigator of Chemical Sciences Division. He is an expert in Synchrotron Radiation and actinide materials, especially in actinide investigation by soft X-ray absorption. He had been the director and project leader of Molecular Environmental Sciences (MES) Beamline 11.0.2 at the Advanced Light Source for a long time. Dr.Shuh got his B.S of Chemistry, University of California Riverside in 1983, M.S of Physical Chemistry, University of California Los Angeles in 1987 and Ph.D of Physical Chemistry at University of California Los Angeles. He is a fellow member of American Chemical Society (ACS), American Physical Society (APS), American Vacuum Society (AVS), Materials Research Society (MRS) and American Association for the Advancement of Science (AAAS). Up to now, he has authored or co-authored over 200 scientific papers and 7 BOOKS/PROCEEDINGS/WORKSHOP REPORTS and over 100 solicited presentations. He has also won many important awards such as Director's Award for Exceptional Achievement (Safety), LBNL; Professor T. J. Delbaere Memorial Award 2010, Canadian Light Source; Inaugural Richard G. Haire Lecture, Chemistry Dept., Auburn University; City of Riverside Sports Hall of Fame, Riverside, CA.