2015-04-02: Dinner Meeting featuring Prof. Karl Christe, USC

Abstract: A review will be given of our research in the field of iodine chemistry including the following topics. Using IF5 as a solvent for halogen fluoride ions, the IF6+, IF6-, I2F11- and I3F16- ions were synthesized and characterized. Subsequently, the IF2-, IF4-, IF4+, and IF4O- ions were prepared. The most interesting species was the IF52- anion which has an unprecedented pentagonal-planar structure. The long-standing problems of the fluxionality of IF7 and the steric activity of the free valence electron pair in the halogen hexafluoride anions were solved. At the limits of coordination and oxidation, the IF5O2-, IF5O22- and IF6O-, the first examples of pentagonal-bipyramidal AX5E2, AX5EO, AX5O2, and AX5YZ species, were prepared, and a novel method for the stepwise replacement of two fluorines in iodine fluorides by an oxygen was developed. With I(ClO4)3 and I(ClO4)4-, the first examples of highly explosive iodine perchlorates were discovered, and fluorocarbon perchlorates were prepared by the reaction of fluorocarbon iodides with halogen perchlorates. Similarly, chlorine fluorosulfate and perfluoroisopropyl iodide yield i-C3F7I(SO3F)2, a compound with an iodonium cation and an iodite anion. Iodine fluorosulfate, ISO3F, can also be added across olefinic double bonds producing iodoperfluorocarbon fluorosulfates. Further examples of the broad scope of this work are the syntheses of FOIF4O, ClOIF4O, HOIF4O, and tetrafluoroperiodates, and the study of the polymorphism in tetramethylammonium periodate. Recently, the potential of I2O6 as an agent for the defeat of weapons of mass destruction was demonstrated. Most of these compounds are not only of academic interest but have many applications as High Energy Density Materials, explosives, propellants, and chemical lasers.

Biography: Dr. Karl O. Christe is a Research Professor with the Loker Hydrocarbon Research Institute and Department of Chemistry at the University of Southern California, Los Angeles, CA. He received his B.Sc. from the Technical University of Stuttgart, Germany, 1957 and the University of Vienna, Austria, 1958, his M. Sc., Technical University of Stuttgart, Germany, 1960 and his Ph. D., Technical University of Stuttgart, Germany, 1961.

Dr. Christe has 53 years of experience in the synthesis of novel high energy oxidizers and rocket propellants and has managed and scientifically directed a large number of government funded research contracts. He has achieved the first syntheses of many spectacular compounds, such as ClF3O, ClF3O2, halogen perchlorates, OIF4OF, OsF4O2, and ions, such as NF4+, ClF6+, ClF6-, ClO2F2-, ClO2F2+, ClF2O+, ClF4O-, NF3+, NF2O+, and NH2F2+. He has invented solid propellant fluorine gas generators for chemical laser weapon systems and has discovered the first purely chemical synthesis of elemental fluorine. He has developed a synthesis for anhydrous tetramethylammonium fluoride and has pioneered the use of this compound as a source of “naked” fluoride ions, which has led to a renaissance of high coordination number chemistry. Among the novel compounds, which he prepared in this manner, are the XeF5- and IF52- anions, which are the first known examples of pentagonal planar species.

Dr. Christe is a member of the American Chemical Society and the Gesellschaft Deutscher Chemiker, and has received numerous awards, including the ACS Award in Iodine Chemistry (2015), the ACS Tolman Award (2011), Elections to the European Academy of Sciences and Arts (2010), and the European Academy of Sciences (2009), the Alfred Stock Gedaechtnispreis of the German Chemical Society (2006), the ACS Award in Inorganic Chemistry (2003), the Prix Moissan (2000), the ACS Award in Fluorine Chemistry (1986), and the NASA Apollo Achievement Award (1969).

Reservations: There will be a buffet dinner. The cost is $25 including tax, tip, iced tea and dessert, cash or check at the door. The talk at 8:00 is free to attend.

Directions: A campus map and directions are available at: http://college.lattc.edu/about-lattc/campus-map/