The Reactivity of Transition Metal Complexes with Ozone
Project Description
This project examines the reactivity of transition metal complexes with O3. There is evidence that complexes where the metal is in an unusually high oxidation state can be prepared with O3 as the primary oxidant. Not only are species of this kind relevant to catalysis by metalloenzymes (e. g., cytochrome P-450, methane monooxygenase), they are of interest because it is known that metal ions promote the oxidation of organic molecules by O3. If the oxidizing power of O3 could be harnessed using an appropriate catalyst, it may be possible to destroy dangerous organic compounds under mild conditions.
The methods that we are using to study these reactions are similar to those used with O2. The metals (V, Cr, Mn, Fe) under consideration are known to support high oxidation states (greater than or equal to +4) and the ligands used stabilize these high-valent states while being resistant to oxidation. The main obstacle that we have encountered is that we must use a mixed O2/O3 gas stream as our O3 source, which means that our starting materials must be in the +3 oxidation state. Metals in lower oxidation states (notably +2) are known to react with O2, and in our experiments, this would be an unwanted side reaction. We have also been examining simpler ligands, such as acetylacetone, to see whether results from the 1950's that seemed to show that reaction of these compounds lead to formation of metal oxides and complete ligand oxidation.
The methods that we are using to study these reactions are similar to those used with O2. The metals (V, Cr, Mn, Fe) under consideration are known to support high oxidation states (greater than or equal to +4) and the ligands used stabilize these high-valent states while being resistant to oxidation. The main obstacle that we have encountered is that we must use a mixed O2/O3 gas stream as our O3 source, which means that our starting materials must be in the +3 oxidation state. Metals in lower oxidation states (notably +2) are known to react with O2, and in our experiments, this would be an unwanted side reaction. We have also been examining simpler ligands, such as acetylacetone, to see whether results from the 1950's that seemed to show that reaction of these compounds lead to formation of metal oxides and complete ligand oxidation.
Background Needed
Project involves a great deal of ligand synthesis, but it also involves some spectroscopy and other physical methods. At least one year of college chemistry, or extensive laboratory experience, is required. Organic chemistry is useful, but not essential.