Prof. Christopher C Cummins

Research interests of the Cummins group encompass (i) new methods for inorganic synthesis, (ii) the synthesis, isolation, and characterization of unusually reactive transition metal and actinide complexes of unique design and construction, (iii) the activation of ubiquitous small molecules including dinitrogen, (iv) the assembly of novel functional groups containing both transition metals and main group elements, and (v) the development of new reagents for organic synthesis.

A general theme in the research is the use of novel voluminous ligands to engender the formation of isolable, low-coordinate metal compounds. These compounds are manipulated and isolated using standard inert-atmosphere glove-box or vacuum-line techniques. The compounds typically are obtained in multigram quantities as colored crystalline solids that dissolve readily in hydrocarbon solvents, and they typically maintain their integrity when kept at a temperature less than or equal to ca. 30 ºC.

A variety of spectoscopic techniques are used to optimize synthetic conditions, to measure reaction kinetics, and to characterize new compounds. Formost among the techniques are multinuclear NMR and single-crystal X-ray experiments.

The new molecules synthesized and studied may challenge current paradigms of molecular structure, bonding, and reactivity. From a practical point of view, the studies serve to provide definitive examples of new reactions that may lead to technological advances. The mechanism-based design of new catalysts for small-molecule transformations ultimately might incorporate reactions first revealed in the context of this project.

Statement of Research Interests: Synthetic inorganic chemistry is the province of the Cummins research team. Overarching goals are to produce unprecedented structural motifs from which definitive examples of new reactions can be obtained. Reactions of particular interest are those involving the manipulation of small molecules including elemental nitrogen (N2) and phosphorus (P4), carbon monoxide and dioxide, the nitrogen oxides, and dihydrogen. Also of particular interest are reactions that illustrate novel manipulation of organic functionality. Air-exclusion techniques are employed for the construction of new metal-ligand complexes, which in turn are characterized by spectroscopic methods and X-ray crystallography prior to reactivity studies. Three distinct project areas are under investigation: (i) low-coordinate complexes of the early transition metals, (ii) arene binding and delta bonding in uranium chemistry along with molecular uranium phosphides and nitrides, and (iii) novel group transfer reagents. While distinct the project areas function synergistically. Density functional theory studies are carried out concurrently with the synthetic work for purposes both interpretive
and predictive.