Toward Activation and Reduction of CO₂ Using Redox Active Complexes

The abundance of carbon dioxide permits its use as a renewable C1 source for the production of more useful products such as liquid fuels. Through activation by a Lewis acid, CO₂ reduction could occur allowing the formation of these products without high activation barriers. Specifically we will use aluminum as the Lewis acid because of its highly electropositive character. Since aluminum is not redox active, an iminopyridine ligand scaffold capable of storing two electrons in the same system could be used to donate electrons to CO₂. Bulky ligands will be used to enforce a low coordination number. When synthesizing the redox active aluminum complexes, ether is bound to the complex. This prevents the binding of CO₂, however this shows that the complex is oxophilic and thus has the potential to activate and reduce CO₂. Further research is being done in order to remove ether from the existing aluminum complexes. This combination of a highly Lewis acidic, low coordinate aluminum center along with a redox active iminopyridine ligand scaffold could allow binding and reduction of CO₂ to more useful products like methanol and formaldehyde.