Professor Karl Otto Christe, University of Southern California, Los Angeles, USA, celebrates his 85th birthday on July 24, 2021. Christe’s research interests include high-energy-density materials. He is a pioneer in the areas of polynitrogen and polyazide compounds, as well as fluorine chemistry. He has synthesized compounds containing, e.g., the nitrogen and halogen oxides NF₄+, ClF₆+, the pentazenium cation N₅⁺, or the pentazolate anion N₅⁻.

Karl O. Christe studied chemistry at the University of Stuttgart, Germany, where he received his Ph.D. in 1961. In 1962, he moved to the U.S., where he worked at Stauffer Research Center in Richmond, CA, USA. He served as a Researcher at Rocketdyne, Canoga Park, CA, USA, from 1967 to 1994. Christe joined the University of Southern California as Professor in 1994. From 1994 to 2005, he additionally worked as Senior Staff Advisor at the Air Force Research Laboratory, Edwards Air Force Base, CA, USA.

Among other awards, Christe has received NASA’s Apollo Achievement Award in 1969, the ACS Award for Creative Work in Fluorine Chemistry from the American Chemical Society (ACS) in 1986, the ACS Award in Inorganic Chemistry in 2003, the Alfred Stock Preis from the Gesellschaft Deutscher Chemiker (GDCh, German Chemical Society) in 2006, the Tolman Award from the ACS in 2011, and the M. Frederick Hawthorne Award in Main Group Inorganic Chemistry from the ACS in 2021. He is a Fellow of the American Association for the Advancement of Science.

Selected Publications

• Protonation of CH₃N₃ and CF₃N₃ in Superacids: Isolation and Structural Characterization of Long‐Lived Methyl- and Trifluoromethylamino Diazonium Ions,
  Thomas Saal, Zsófia E. Blastik, Ralf Haiges, Archith Nirmalchandar, Amanda F. Baxter, Karl O. Christe, Monica Vasiliu, David A. Dixon, Petr Beier, G. K. Surya Prakash,
  Angew. Chem. Int. Ed. 2020, 59, 12520–12526.
  https://doi.org/10.1002/anie.202002750
• Energetic Properties, Spectroscopy, and Reactivity of NF₃O,
  Monica Vasiliu, Tarek Trabelsi, Joseph S. Francisco, Karl O. Christe, David A. Dixon,
  J. Phys. Chem. A 2020, 124, 5237–5245.
  https://doi.org/10.1021/acs.jpca.0c03733
• Difluorochloronium(III) Fluoridometallates – from Molecular Building Blocks to (Helical) Chains,
  Benjamin Scheibe, Ralf Haiges, Sergei I. Ivlev, Antti J. Karttunen, Ulrich Müller, Karl O. Christe, Florian Kraus,
  Eur. J. Inorg. Chem. 2020, 2020, 4483–4496.
  https://doi.org/10.1002/ejic.202000845
• Long-Lived Trifluoromethanide Anion: A Key Intermediate in Nucleophilic Trifluoromethylations,
  G. K. Surya Prakash, Fang Wang, Zhe Zhang, Ralf Haiges, Martin Rahm, Karl O. Christe, Thomas Mathew, George A. Olah,
  Angew. Chem. Int. Ed. 2014, 53, 11575–11578.
  https://doi.org/10.1002/anie.201406505
• Recent Advances in the Chemistry of N₅⁺, N₅⁻ and High-Oxygen Compounds,
  Karl O. Christe,
  Propellants Explos. Pyrotech. 2007, 32, 194–204.
  https://doi.org/10.1002/prep.200700020
• High-Energy-Density Materials: Synthesis and Characterization of N₅⁺ [P(N₃)₆]⁻, N₅⁺ [B(N₃)₄]⁻, N₅⁺ [HF₂]⁻·n HF, N₅⁺ [BF₄]⁻, N₅⁺ [PF₆]⁻, and N₅⁺ [SO₃F]⁻,
  Ralf Haiges, Stefan Schneider, Thorsten Schroer, Karl O. Christe,
  Angew. Chem. Int. Ed. 2004, 43, 4919–4924.
  https://doi.org/10.1002/anie.200454242
• Complex Fluoro Cations. II. Tetrafluoronitrogen(V) Cation, NF₄⁺. Synthesis and Properties of NH₄⁺AsF₆^–,
  Jacques P. Guertin, Karl O. Christe, Attila E. Pavlath,
  Inorg. Chem. 2002, 5, 1921–1924.
  https://doi.org/10.1021/ic50045a018
• 3.0.CO;2-T” target=”_blank”>https://doi.org/10.1002/1521-3773(20020816)41:16<3051::AID-ANIE3051>3.0.CO;2-T
• 3.0.CO;2-7″ target=”_blank”>https://doi.org/10.1002/(SICI)1521-3773(19990712)38:13/14<2004::AID-ANIE2004>3.0.CO;2-7
• The hexafluorochlorine (VII) cation, CIF₆⁺,
  Karl O.Christe,
  Inorg. Nucl. Chem. Lett. 1972, 8, 741–745.
  https://doi.org/10.1016/0020-1650(72)80129-6