On April 12, 2018, with the invitation of Prof. Wu, Prof. Henry F. Schaefer III visited our school and gave a wonderful lecture titled “Some Chemistry Involving Hypervalent Iodine” respectively.

       The report of Professor Henry F. Schaefer III starts from two aspects. Firstly, the progress of Computational Chemistry in the study of hypervalent iodine reagent Togni I was introduced. Compounds are usually found in nature as low-energy isomers, while Togni I reagents exist as high-energy isomer, and Prof.Schaefer's team used computational chemistry to elucidate the reasons behind them. They found that the energy barrier for the conversion of Togni I reagents from high-energy isomer to low-energy isomer was too high to be achieved at room temperature, and the structure of the synthetic precursor was similar to that of high-energy isomer,therefore it was in the form of high-energy isomer exist. The second part introduces the research progress on the mechanism study of hypervalent iodine reagent IBX oxidation. Through comparative study of a series of calculation methods and comparative analysis with the experimental results, the reductive elimination as the rate-determining step was elucidated. It was found that the linker of IBX five-membered ring has a great influence on the oxidation activity of IBX. Based on this, the iodide and oxidant combination with higher oxidation activity was designed and finally verified by kinetic experiments.(Written by Heming Jiang)

Brief introduction of speakers:

Henry F. Schaefer III, born in Grand Rapids, Michigan, America. He was awarded a B.S. degree in chemical physics by the Massachusetts Institute of Technology in 1966 and a Ph.D. degree in chemical physics from Stanford University in 1969. He was professor of Chemistry at the University of California, Berkeley from 1969 to 1987. In 1979 to 1980, he was Wilfred T. Doherty Professor of Chemistry and inaugural director of the Institute for Theoretical Chemistry at the University of Texas, Austin. Since 1987, he was professor of Chemistry and director of the Center for Computational Quantum Chemistry at the University of Georgia. He is also a fellow of the American Academy of Arts and Sciences. Prof. Schaefer has been engaged in theoretical and computational chemistry research. He has made outstanding contributions in the field of structural properties of metal organic catalysts and in the research and calculation of high-precision quantum chemical theory methods, and has achieved a series of internationally recognized iconic academic achievements. Prof. Schaefer has published nearly 1500 papers in international academic journals such as Nature, JACS, Angew, etc. The total number of citations reached up to 57,000, H factor 108. In 2000, Prof. Schaefer was listed as one of the highest citation rate chemists in the world from 1981 to 1997. In February 2014, Prof. Schaefer was selected as the "50 most influential scientists in the world today."