Marlan Witte

Synthesis of a Copper-Sulfur Cluster Supported by N-Heterocyclic Carbene Ligands

Climate change has been a global issue that has changed environments at a more rapid rate than ever before. Production of massive amounts of carbon dioxide and nitrous oxide in industry and fuel usage has dramatically increased the concentration of these gases in the atmosphere. Carbon dioxide prevents heat from exiting the atmosphere and raises the average global temperature and nitrous oxide destroys ozone which is the protective gas from ultraviolet radiation. Development of a method to remove these gases and potentially make them useful to us is imperative. Molecular models of enzymes that have similar reactivity and copper-sulfur surfaces have been developed to produce reduced products of these two gases. These attempts have had significant success with developing reactivity and partial selectivity, but not complete catalytic ability. Utilizing copper-sulfur clusters supported by tunable N-heterocyclic carbene (NHC) ligands has the potential as a stable and selective catalyst. The strong donating ability of the NHCs will form a stable cluster and these clusters can be made with different NHCs which gives them a potential tunable property for product selectivity. Currently, the synthesis and characterization of a diisopropylphenyl analog (IPr) NHC-supported cluster are underway. Characterization is performed by NMR and single crystal X-Ray diffraction for confirmation of structures. Two predominant products and a shift in the more predominant one during the workup are observed and being investigated.