A Nonoxidative Approach to Methane Functionalization: Efforts Towards Realizing the Methanol Economy

Methane, CH₄, is considered a pillar of the petrochemical industry. It is a major component of fossil fuels, a byproduct of waste decomposition, and a potent greenhouse gas. The potential of methane as a fuel source is greatly limited by the means in which this flammable gas may be transported. In this regard, functionalization of CH₄ to yield products that are liquids under ambient conditions holds great promise. We have made efforts towards facile methane functionalization under mild, nonoxidative conditions. It has been found that d¹⁰ transition metal ions supported by tripodal tris(2-iminoethyl)amine ligands rapidly isomerize, shifting between different coordination geometries, much like behavior observed at protein active sites. When these complexes are paired with a bulky base, sterically frustrated Lewis pairs (FLPs), which are known to heterolytically cleave bonds in a variety of small molecules, are formed. In this presentation, our work with zinc-based FLPs will be discussed. Specifically, the room temperature C-H bond activation of methane facilitated by these FLP systems and ongoing efforts towards methanol production will be described.