Catalytic Activation of C-H/C-C Bonds by Electrophilic Metal Compounds

This award to Ayusman Sen of The Pennsylvania State University from the Inorganic, Bioinorganic and Organometallic Chemistry Program is for study of metal mediated electrophilic activation of carbon-hydrogen and carbon-carbon bonds in hydrocarbons leading to the oxidative functionalization of alkanes and arenes. Especially important as a potential outcome of this research would be the catalytic oxidation of methane to methanol, an excellent and conveniently transportable energy source. The general approach will be to employ highly electrophilic, weakly ligated metal species such as the lanthanide(III) tri- fluoroacetate complexes in trifluoroacetic acid solvent. The study will address five major points: (a) the relationship between the propensity to cause electrophilic cleavage of C-H bonds and the nature of the metal, (b) the relative tendencies of the different classes of C-H bonds to undergo electrophilic cleavage, (c) the ability of different types of cooxidants to reoxidize the metal species in the catalytic cycle, (d) the possibility of using the metal solely as an electrophile and a separate two-electron oxidant to oxidize the metal-bound hydrocarbyl species, and (e) the possibility of achieving the electroplilic cleavage of C-C bonds.