This award in Inorganic, Bioinorganic and Organometallic Chemistry program supports work by John P. Caradonna to explore the chemistry exhibited by a class of binuclear non-heme ferrous complexes that are capable of catalyzing the oxidation of alkanes to alcohols in the presence of either oxygen atom donor molecules or alkyl hydroperoxides. Catalytic alkane oxidation and functionalization is an area of intense scientific and commercial interest due the potential for converting inexpensive aliphatic hydrocarbons to valuable chemical and fuel products. The proposed approach uses a combination of synthetic, mechanistic, and spectroscopic methods to investigate the catalytic chemistry of complexes, which are designed based on principles obtained from metalloenzyme studies and mimic two fundamental process exhibited by many non-heme iron monooxygenases. These processes are the heterolytic cleavage of a bound peroxide ligand and the efficient transfer of the oxygen atom to substrate. The work focuses on two fundamentally different, although related aspects of alkane oxidation: 1) Development of a molecular-level understanding of the mechanism by which binuclear ferrous compounds catalyze the oxidation of alkanes and arenes, and 2) Exploration of the chemical nature and electronic characteristics of the iron-based reactive intermediate(s) responsible for the formal transfer of an oxygen atom to an alkane substrate.
Although alkanes and biological materials are attractive feedstocks, their use is currently restricted primarily to fuels because of the limited number of available reactions for their modification. This work is directed toward a deeper understanding of the fundamental reaction chemistry and the development of useful reagents for the controlled oxidation of substrates such as alkanes and arenes. This project also affords an opportunity for graduate and undergraduate students to participate in a collaborative learning environment. As a participant in the American Chemical Society's SEED program, Prof. Caradonna has also opened his laboratory to minority high school students who perform 10 weeks of research in which they are also exposed to college life in general. The research activities associated with the proposed program and Professor Caradonna's educational projects generate a wide range of experiences, depth of knowledge, and communication skills necessary for the development of accomplished young scientists.