Christe Research Group








Research Focus

Our interests are very broad and range from very basic studies to applied research of academic, Government or industrial interest. We are particularly interested in high energy density materials (HEDM), inorganic main group chemistry, polynitrogen and nitramine chemistry, high-oxygen carriers for the replacement of the presently used toxic ammonium perchlorate and hydrazine-based propellants by higher-performing  green compounds, energetic ionic liquids, chemistry at the limits of oxidation and coordination, the synthesis and characterization of novel carbocation and fluorocarbon compounds, and the development of quantitative scales for fundamental properties, such as Lewis acidity, oxidizer strength and the “nakedness” of fluoride ion sources. Our work exploits the synergism of theory and synthesis and greatly benefits from close collaborations with several groups of theoreticians. The main goal of our research is to advance the state of the art and strive for spectacular breakthroughs, rather than settling for small incremental improvements.

In the following section, some typical examples of our work in different areas are highlighted. Because of space limitations, we have omitted a vast body of work in the areas of halogen fluorides, inorganic halogen oxidizers and singlet delta oxygen gas generators. The pertinent references to these data can be found in the publications list in the bio of Karl Christe by clicking on his picture.

Novel oxygen-balanced, energetic ionic liquids of interest for liquid monopropellants:
(C. Bigler Jones, Ralf Haiges, Thorsten Schroer, and Karl O. Christe, Angew. Chem. Int. Ed. 2006, 45, 4981)


Polynitrogen Chemistry: One of the discoveries, which has received coverage even in the New York Times (Feb 2, 1999) and London Times (Feb 10, 1999) and was selected by Chem. & Eng. News as one of chemistry’s top five achievements of 1999, is the single-step synthesis of the N5+ cation in essentially quantitative yield and the determination of its structure. The N5+ cation is only the second homonuclear polynitrogen species that has been isolated in bulk and may provide the basis for new high-energy-density materials.

Polyazide Chemistry: During the past seven years, Ralf Haiges from our group has prepared and characterized a very large number of polyazido compounds. Typical examples are shown below.

"Naked Fluoride” and High Coordination Number Chemistry:

Chemical Synthesis of Elemental Fluorine:

Onium Salts:

NF4+ Chemistry:

Convenient Access to Trifluoromethanol:
(Karl O. Christe, Joachim Hegge, Berthold Hoge, Ralf Haiges, Angew. Chem. Int. Ed. 2007, 46, 6155)

Quantitative Scales for Oxidizing Power, Lewis Acidity and “Nakedness of Fluoride Ion Sources: